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The Caucasian Rock Lizard Lacerta rostombekovi: a Monoclonal Parthenogenetic Vertebrate
Abstract
Among vertebrates, true parthenogenesis (self-perpetuating all-female species) occurs only in reptiles; these species are of hybrid origin. To date, all diploid parthenogenetic reptiles examined exhibit some genetic diversity, resulting in the existence of more than one clone. The sole exception to this is the Caucasian rock lizard Lacerta rostombekovi, which appears to consist of only a single clone. © 1997 Elsevier Science Ltd. All rights reserved Introduction Although well-documented, the phenomenon of parthenogenesis is not well under-stood. Questions dealing with the ecology, genetics, frequency of hybridization, genealogical constraints on parthenogenesis, and mechanisms for failed meiosis are paramount. Among vertebrates, true parthenogenesis has been detected only in squamate reptiles, and especially among lizards (Vrijenhoek et al., 1989). All diploid parthenogenetic species examined have been shown to exhibit intraspecific genetic diversity; each 'species' consists of multiple clones, caused by either mutation, multiple origins or genetic recombination (Cole et al., 1 988; Parker, 1 979a; Parker and Selander, 1984). Clonal diversity has been related to distribution, ecological parameters, and inferred age of parthenogenetic species (Dessauer and Cole, 1989; Parker, 1979b). Because of their origin through hybridization, parthenogenetic species exhibit char-acteristics of F1 hybrids, including a high level of fixed heterozygosity. In hybridogenesis there must be a balance between too much genetic divergence between parental species, which would result in developmental failure, and hybridization, permitting viable offspring and backcrossing. This has been termed the 'balance hypothesis' (Moritz et al., 1989). The relationships among potential parental species require further study. The genus Lacerta contains several parthenogenetic species, all of which were formed by hybridization between bisexual species; in fact, parthenogenesis in reptiles was first discovered in this genus (Darevsky, 1958). One of these unisexual species, L. ros-tombekovi, arose from the hybridization of a male L. portschinskii and a female L. raddei (Darevsky et al., 1985; Moritz et al., 1992; Murphy et al., in press). The two parental tCorresponding author (ROSSM@ROM.ON.CA).
... Despite some success in the study of D. rostombekowi (MacCulloch et al., 1997;Martirosyan et al., 2002;Osipov et al., 2016;Ryskov et al., 2017), questions about the boundaries of its range and speciesspecific parameters of abiotic environmental factors (determining the area of distribution of isolated populations) remain unclear. The analysis of allozyme loci in individuals of different D. rostombekowi populations (except for the isolated Tsovak population) revealed no variability, which presumably indicated a monoclonal genetic structure (MacCulloch et al., 1997). ...
... There are fragmentary data on the distribution of isolated populations of D. rostombekowi in Armenia. It is known that the D. rostombekowi lizard (one of seven parthenogeneticspecies of Darevskia rock lizards) occupies a relatively small range consisting of several isolated populations of different sizes within Northern Armenia, adjacent regions of Northwest Azerbaijan, and a small alpine relict (~12000 years) population (detached from the main range) on the southeastern coast of Lake Sevan (MacCulloch et al., 1997;Martirosyan et al., 2002;Arakelyan et al., 2011, Petrosyan et al., 2020a. The boundaries of the range of the species , as well as of isolated populations, are absent in the literature. ...
... Vector layers of the occurrence records. Field, museum, and literature data were used to create a vector database (VDB) in the ArcGIS Desktop 10.4.1 environment (Darevsky, 1967;Uzzell and Darevsky, 1975;MacCulloch et al., 1997;Martirosyan et al., 2002;Arakelyan et al., 2011;Ryskov et al., 2017). ...
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The results of the analysis of the genetic variability of parthenogenetic Darevskia rostombekowi (Darevsky, 1957) species using four microsatellite-containing loci are presented. Based on 118 records with geographical coordinates of the presence of this species in Transcaucasia, the maps of potential range were created. The analysis of the genetic structure of populations demonstrated that despite the established multiclonality (seven clonal lines in four populations), D. rostombekowi was formed as a result of a single act of hybridization between closely related bisexual species. The predicted distribution of D. rostombekowi using the modelling of potential range revealed new suitable habitats, where the presence of the species has not been reported previously. The results of this study and the absence of multiple acts of hybridization during the formation of these clones may indicate a regression of population size of the species. Consequently, the estimation of the conservation status of this parthenogenetic species seems to be justified.
... This species has a diploid chromosome set, high fixed heterozygosity of allozyme loci and low variation of mitochondrial DNA [11][12][13][14]. The allozyme data for 35 loci of D. rostombekovi (sample of 65 animals) did not show variation in populations of this species [15]. Thus, in contrast to D. dahli, D. armeniaca , and D. unisexualis , D. rostombekovi is considered a monoclonal species. ...
... They may be caused by RFLP mutations [27,28], mutations in hypervariable mini-and microsatellite loci 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2021 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2021 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 [ [29][30][31][32][33][34][35][36] including those previously analyzed in D. dahli, D. armeniaca, and D. unisexualis, and chromosome rearrangements of genetically unstable hybrid karyotypes [38,39]. The data on variation of mini-and microsatellite DNA markers are particularly interesting in view of the allozyme studies showing that D. rostombekovi populations represent a single clone [15], i.e., this species is monoclonal. The discrepancy between the allozyme and nuclear DNA data may be explained by different mutation rates in coding and repetitive DNA regions as well as in the genome as a whole. ...
... represent a similar geographic chromosomal race and/or clone that appeared due to a series of chromosomal mutations having occurred during karyological evolution of the species. On the other hand, the authors who described the monoclonal structure of the D. rostombekovi population according to allozyme loci [15], did not examine lizards from the population of southeastern Sevan. Combined studies using different systems of genetic markers may help to revise the population structure, origins, and evolutionary history of this species. ...
Variation and clonal diversity in populations of the parthenogenetic rock lizard Darevskia rostombekovi was examined by means of multilocus DNA fingerprinting using mini- and microsatellite DNA markers M13, (GATA)_4, and (TCC)_50). The animals examined were shown to exhibit a clonally inherited, species-specific pattern of DNA markers (fingerprint profile) that is different from the species-specific patterns of parthenogenetic species D. dahli, D. armenica, and D. unisexualis. The mean intraspecific similarity index S was 0.950 (0.003) for a sample of 19 animals from three isolated populations of North Armenia. This significantly differed from the estimate of this parameter for a sample of 21 animals including two individuals from mountainous, relict population from the vicinity of the Sevan Lake, which was equal to 0.875 (0.001). A comparison of DNA fingerprints showed differences between 21 individuals attaining 79 DNA fragments of 1801 mini- and microsatellite markers included in the analysis. The results obtained show that intraspecific variation in D. rostombekovi is higher than that in the previously studied parthenogenetic species D. dahli (S = 0.962) and D. unisexualis (S = 0.950) (P Document Type: Regular Paper Affiliations: 1: State Research Institute for Genetics and Selection of Industrial Microorganisms, Moscow, 113545 Russia 2: Institute of Gene Biology, Russian Academy of Sciences, Moscow, 117334 Russia ryskov@mail.ru 3: Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, 117984 Russia 4: Yerevan State University, Yerevan, 375000 Armenia 5: Institute of Zoology, Russian Academy of Sciences, St Petersburg, 199034 Russia Publication date: June 1, 2002 $(document).ready(function() { var shortdescription = $(".originaldescription").text().replace(/\\&/g, '&').replace(/\\, '<').replace(/\\>/g, '>').replace(/\\t/g, ' ').replace(/\\n/g, ''); if (shortdescription.length > 350){ shortdescription = "" + shortdescription.substring(0,250) + "... more"; } $(".descriptionitem").prepend(shortdescription); $(".shortdescription a").click(function() { $(".shortdescription").hide(); $(".originaldescription").slideDown(); return false; }); }); Related content In this: publication By this: publisher By this author: Martirosyan, I.A. ; Ryskov, A.P. ; Petrosyan, V.G. ; Arakelyan, M.S. ; Aslanyan, A.V. ; Danielyan, F.D. ; Darevsky, I.S. ; Tokarskaya, O.N. GA_googleFillSlot("Horizontal_banner_bottom");
... A recent series of molecular studies have examined population variation in Caucasian rock lizards. Moritz et al. (1992) using mtDNA restriction fragment analysis, and MacCulloch et al. (1995, Murphy et al. (1997), and Fu et al. (1998) employing allozyme electrophoresis, examined divergence of the parthenogenetic species. Little variation was found. ...
... Parentage of the parthenogens.-Lacerta raddei is the maternal parent of L. unisexualis and L. rostombekowi, with L. valentini and L. portschinskii being the paternal parents, respectively (Darevsky, 1992;MacCulloch et al., 1997;Fu et al., 1998). This study identified L. raddei as the maternal parent of L. uzzelli, and a recent allozyme study showed that L. valentini was the paternal species ( J. Fu, R. D. MacCulloch, R. W. Murphy, I. S. Darevsky, and B. S. Tuniyev, unpubl.), as Darevsky and Danielyan (1977) originally proposed. ...
... This low level of divergence is also concordant with the allozyme data, which reveals very little clonal variation. Only one clone has been detected in L. rostombekowi ; three in L. armeniaca (MacCulloch et al., 1995), three in L. unisexualis (Fu et al., 1998); and five in L. dahli . ...
Questions concerning the origin of parthenogenesis in Caucasian Rock Lizards and genetic divergence among bisexual lizards of the Lacerta raddei complex were examined using sequences from the mitochondrial cytochrome b gene. The maternal parent of the parthenogenetic L. uzzelli, L. sapphirina, and L. bendimahiensis was confirmed to be L. raddei. Although substantial variation was revealed among bisex- ual populations of L. raddei and L. nairensis, very low or no variation was found among the parthenogenetic species. A phylogenetic tree including 11 populations of L. raddei and L. nairensis, as well as 10 populations of its five daughter parthen- ogens, was constructed. Because of paraphyletic relationships, L. nairensis is consid- ered conspecific with L. raddei. Evaluation of the parthenogenetic species suggests that separate hybridization events between L. raddei and L. valentini might have occurred at least twice. One resulted in L. sapphirina and L. bendimahiensis, and the other one (or more) resulted in L. unisexualis and L. uzzelli. The females involved were distantly related. Lacerta unisexualis and L. uzzelli likely had separate origins, but the females involved were closely related.
... This species has a diploid chromosome set, high fixed heterozygosity of allozyme loci and low variation of mitochondrial DNA11121314. The allozyme data for 35 loci of D. rostombekovi (sample of 65 animals) did not show variation in populations of this species [15]. Thus, in contrast to D. dahli, D. armeniaca , and D. unisexualis , D. rostombekovi is considered a monoclonal species. ...
... 2.2930313233343536 including those previously analyzed in D. dahli, D. armeniaca, and D. unisexualis, and chromosome rearrangements of genetically unstable hybrid karyo- types [38, 39]. The data on variation of mini-and microsatellite DNA markers are particularly interesting in view of the allozyme studies showing that D. rostombekovi populations represent a single clone [15], i.e., this species is monoclonal. The discrepancy between the allozyme and nuclear DNA data may be explained by different mutation rates in coding and repetitive DNA regions as well as in the genome as a whole. ...
... represent a similar geographic chromosomal race and/or clone that appeared due to a series of chromosomal mutations having occurred during karyological evolution of the species. On the other hand, the authors who described the monoclonal structure of the D. rostombekovi population according to allozyme loci [15], did not examine lizards from the population of southeastern Sevan. Combined studies using different systems of genetic markers may help to revise the population structure, origins, and evolutionary history of this species. ...
Variation and clonal diversity in populations of the parthenogenetic rock lizard Darevskia rostombekovi was examined by means of multilocus DNA fingerprinting using mini- and microsatellite DNA markers M13, (GATA)4, and (TCC)50). The animals examined were shown to exhibit a clonally inherited, species-specific pattern of DNA markers (fingerprint profile) that is different from the species-specific patterns of parthenogenetic species D. dahli, D. armeniaca, and D. unisexualis. The mean intraspecific similarity index S was 0.950 (0.003) for a sample of 19 animals from three isolated populations of North Armenia. This significantly differed from the estimate of this parameter for a sample of 21 animals including two individuals from mountainous, relict population from the vicinity of the Sevan Lake, which was equal to 0.875 (0.001). A comparison of DNA fingerprints showed differences between 21 individuals attaining 79 DNA fragments of 1801 mini- and microsatellite markers included in the analysis. The results obtained show that intraspecific variation in D. rostombekovi is higher than that in the previously studied parthenogenetic species D. dahli (S = 0.962) and D. unisexualis (S = 0.950) (P < 0.001). Taking into account that D. rostombekovi is considered monoclonal on the basis of allozyme data, the problem of clonal variability is discussed with regard to the evidence on nuclear DNA markers. It is suggested that the hybrid karyotype of D. rostombekovi, which is more unstable than that of D. dahli and D. unisexualis, generates a series of chromosomal rearrangements (mutations). This may lead to the appearance of a geographically isolated chromosomal race (clone) in the population inhabiting the southeastern coast of the Sevan Lake.
... Comparatively, parthenogenetic D. dahli and D. armeniaca also have one common clone and several rare ones [40]. Only parthenogenetic D. rostombekowi exhibited a single allozyme clone [43]. The level of diversity in D. unisexualis was also similar to that found in parthenogenetic Aspidoscelis neomexicanus [44], which also has a hybrid origin. ...
... Analyses involving 109 individuals of D. unisexualis from seven populations in Armenia identify 12 clones that differ in their frequencies and population distribution. Analyses of 35 allozyme loci in parthenogenetic D. dahli [40], D. rostombekowi [43], and D. armeniaca [45] resolved five, one, and four clones, respectively, while our genomic approach resolves 11 clones in D. dahli [37], five in D. rostombekowi [38], and 13 in D. armeniaca [39]. Thus, assessments of microsatellites discover more variation than allozymes. ...
Background:
The hybridization of female D. raddei and male D. valentini gave rise to the parthenogenetic Caucasian rock lizard Darevskia unisexualis. A previously identified genetic polymorphism in the species consisted of one common and two allozyme clones. Analysis of microsatellites and single nucleotide polymorphisms (SNPs) from the three species yields estimates of clonal diversity and tests the hypothesis of a single origin for D. unisexualis.
Results:
Genotyping and sequencing of four microsatellite-containing loci for 109 specimens of D. unisexualis, 17 D. valentini, and 45 D. raddei nairensis identified 12 presumptive clones, including one widespread and 11 rare clones. Most individuals in some localities had a rare clone. Clone-specific alleles in D. unisexualis were compared with those of the parental species. The results inferred a single hybridization event. Post-formation mutations best explain the less common clones.
Conclusions:
Interspecific analyses identify alleles inherited by D. unisexualis from its bisexual ancestors. SNP analyses fail to reject the hypothesis of a single interspecific origin of D. unisexualis, followed by microsatellite mutations in this initial clone. Microsatellites detect higher clonal diversity in D. unisexualis compared to allozymes and identify the likely origins of clones. Our approach may be applicable to other unisexual species whose origins involve interspecific hybridization.
... The aneuploid gametes that would result from this meiosis would then be unable to create viable progeny (but see Stöck et al., 2002) and, as a consequence, perpetuating lineages of triploid organisms are extremely unusual. However, triploids still occur in unisexual forms of fishes (Comai, 2005), amphibians (Bi et al., 2008), and reptiles (Booth and Schuett, 2016;Macculloch et al., 1997;Taylor et al., 2001;Walker et al., 1997). Usually, these organisms are issued from hybridization between sexual species, are almost all females, and reproduce without sex by parthenogenesis, gynogenesis, or hybridogenesis (Stöck et al., 2002). ...
... For instance, parthenogenesis is observed in triploid hybrids of the genera Cnemidophorus (Hardy and Cole, 1981;Parker and Selander, 1976;Taylor et al., 2001;Walker et al., 1997) and Lacerta (Macculloch et al., 1997). These females are able to produce unreduced eggs and reproduce clonally without the intervention of males. ...
Triploid vertebrates from unisexual complexes often perpetuate themselves asexually. In the fish Chrosomus eos×eos-neogaeus, triploids are continuously produced by diploid hybrids. However, they are not expected to perpetuate since C. eos are their only known progeny. This study aims to investigate the oogenesis of these triploid hybrids through experimental crosses. A total of 337 larvae from 12 female triploids and three 2n/3n mosaics fertilized with C. eos sperm were genetically characterized. The detection of C. eos as progeny of triploid hybrids confirmed the occurrence of a pathway similar to meiotic hybridogenesis but only for half of the tripoids. The presence of tetraploid offspring for all these females revealed the formation of unreduced triploid eggs as a probable failure of meiotic hybridogenesis. The remaining female triploids and all mosaics produced diploid and triploid hybrids. Triploids excluded the haplome from paternal leakage and produced eggs with the diploid hybrid genome through an ameiotic hybridogenesis. Both types of hybridogenesis occurred in a mutually exclusive manner. This leads us to consider two hypothetical scenarios: First, any female triploids can perform either type of hybridogenesis, allowing the long-term persistence of triploid hybrids by a fraction of the population. Alternatively, ameiotic hybridogenesis occurs in triploids of the first generation (from diploid mothers), while meiotic hybridogenesis occurs in triploids of the second generation (from triploid mothers); triploid hybrids then are not perpetuating lineages. The population dynamics of the Chrosomus eos-neogaeus complex appears a step more complicated than previously expected.
... Биогеографические исследования показали, что ящерицы D. rostombekovi занимают сравнительно ограниченный ареал, состоящий из изолированных популяций в Северной Армении и прилежащих районах Азербайджана и изолированной высокогорной популяции на юго-восточном побережье озера Севан (окрестности селения Загалу). Аллозимный анализ различных популяций D. rostombekovi (за исключением популяции Загалу) не выявил у них аллозимной изменчивости и было предположено, что этот вид имеет моноклональную генетическую структуру [8] в отличие от партеновидов D. dahli, D. armeniaca и D. unisexualis, у которых обнаружено от 2 до 5 аллозимных клонов [9]. Генетическая гомогенность популяций D. rostombekovi, обнаруженная по данным аллозимного анализа, не соответствует данным морфологических исследований, согласно которым они имеют значительные различия [3]. ...
... У Pasteurella multocida выявлено 5 капсульных групп (A, B, D, e и F), имеющих различное эпизоотологическое значение для животных. Штаммы бактерии капсульных групп А и D участвуют в возникновении респираторных болезней телят и взрослых животных, В и Е -геморрагической септицемии КРС и буйволов; F -редко выделяли при септических и респираторных болезнях телят [8,9]. У Mannheimia haemolytica выявлено 12 серологических типов, из которых только один (А1) вызывает респираторные болезни КРС [10]. ...
One of the main questions-in the study of the unisexual (parthenogenetic) species of vertebrates is the determination of their genetic diversity. Nuclear and mitochondrial genetic markers can be used for this purpose. One of the most effective genetic markers is the microsatellite DNA, which mutates at a high rate. Development and characteristics of such markers are necessary in studies of parthenogenetic species. In this work, the analysis of the allele polymorphism of three microsatellite loci was performed for the first time via locus-specific PCR in the populations of parthenogenetic species Darevskia rostombekovi (n = 42) and bisexual parental species D. raddei (n = 6) and D. portschinskii (n = 6). All examined individuals of the parthenogenetic D. rostombekovi were heterozygous. Two to five alleles, depending on the locus, were found in the studied populations of the parthenogenetic species. It was shown that the differences were due to the varying structure of the microsatellite cluster and to single nucleotide substitutions at fixed distances in the DNA regions adjacent to the cluster. The allele structure variations form haplotype markers specific for each allele and inherited from the parental bisexual species. It was determined which alleles of the parthenogenetic species were inherited from the maternal species and which from the paternal species. Characteristics of distribution, frequency of occurrence, and combination of alleles of microsatellite loci, which determine the distinctive features of each D. rostombekovi population were obtained. The data can be used in the future to determine the clonal diversity and possible ways of its formation in the populations of the parthenogenetic species D. rostombekovi.
... Darevskia rostombekowi have a chromosome set of 2n = 38 [36], are characterized by fixed heterozygosity of allozyme loci [34] and exhibit low variability of restriction sites of mitochondrial DNA inherited from D. raddei [24]. Studies of 35 allozyme loci from populations in northwestern and central Armenia revealed no allozyme variability, which suggested that this species could be monoclonal [30]. This was unlike the parthenogenetic species D. dahli, D. armeniaca, and D. unisexualis, in which several allozyme clones were found [31]. ...
... Given that lizards with identical genotypes represent a distinct clone, the several microsatellite clones of D. rostombekowi reject the hypothesis of monoclonality based on allozymes [30]. However, it corresponds with the considerable amount of morphological variation in this species [13]. ...
The all-female Caucasian rock lizard Darevskia rostombekowi and other unisexual species of this genus reproduce normally via true parthenogenesis. Typically, diploid parthenogenetic reptiles exhibit some amount of clonal diversity. However, allozyme data from D. rostombekowi have suggested that this species consists of a single clone. Herein, we test this hypothesis by evaluating variation at three variable microsatellite loci for 42 specimens of D. rostombekowi from four populations in Armenia. Analyses based on single nucleotide polymorphisms of each locus reveal five genotypes or presumptive clones in this species. All individuals are heterozygous at the loci. The major clone occurs in 24 individuals and involves three populations. Four rare clones involve one or several individuals from one or two populations. Most variation owes to parent-specific single nucleotide polymorphisms, which occur as heterozygotes. This result fails to reject the hypothesis of a single hybridization founder event that resulted in the initial formation of one major clone. The other clones appear to have originated via post-formation microsatellite mutations of the major clone.
... It was shown that variability levels of partenogenetic species with respect to the skin color and pattern, allozyme loci, histocompatibility, and finally, nuclear DNA markers cannot be compared [8,19,[38][39][40]. If clonal diversity is estimated in respect to each system of morphological and genetic characters, then partenogenetic lizards of the genus Darevskia should be considered as a multiclonal species system. ...
... It is still unknown whether they include already developed clones (and/or populations), which would be in fact different from each other in different parameters (morphological, biochemical, immunological, and cytogenetic characters) or whether mutation processes at different gene loci form a variegated, chaotic picture of genetic diversity and false multiclonality, pointing rather to the early stages of differentiation and clone formation in these species. Notes: The data on allozyme analysis are form [22][23][24][38][39][40], and data on fingerprint analysis are from [18][19][20][21]29]. * Includes the individuals distinguished for at least one marker DNA fragment [19,29]. ...
Using our results and literature data on multilocus DNA fingerprinting, we propose a method of obtaining unbiased estimates of the between-population genetic similarity index and a measure of population subdivision based on modified Wright's FST-statistics. On the basis of multiple comparison T2 Hotelling's test and Holmes' procedure, the FST-statistics was applied to assess differentiation of four (Pacific and Atlantic) subpopulations of humpback whale Megaptera novaeangliae, six populations of Californian island gray fox Urocyon littoralis, and geographically isolated Ob' and Yakutia populations of Siberian white crane Crus leucogeranus. It was shown that the regional humpback whale subpopulations do not constitute a single panmictic unit (P –4). The subdivision index of the Pacific and Atlantic populations expressed in terms of F-statistics varied from 0.101 to 0.157. The differentiation estimates for the island fox populations, which ranged from 0.2109 to 0.4027, indicate that subdivision of these populations is a function of the distance between the islands, island size, and population size. In particular, the smallest and the greatest differences were found respectively between the populations of the geographically closest northern islands (FST = 0.2157, FST = 0.2109) and between those of the most distant northern and southern islands (FST = 0.4027, FST = 0.3869). Subdivision of the island populations with minimum areas and low population number was intermediate (FST = 0.3789). Mean values of heterozygosity, within-population genetic similarity index, and the number of coinciding fragments for two random individuals of Siberian white crane from the Ob' and Yakutia population were not statistically significantly different (P ≥ 0.852, P ≥ 0.491, P ≥ 0.325). However, pairwise comparisons of mean FST values indicated that the differentiation estimates for samples from these populations fall within the limits of population subdivision (P = 0.01). The subdivision estimate (0.108–0.133) of various groups of Siberian white cranes is comparable to interregional subdivision of humpback whale. Based on the results of this study, we recommend the approach based on modified Wright's FST-statistics for studying genetic population structure aimed at detecting population subdivision.
... Nevertheless, they noted that possible multiple origins for D. dahli should be investigated further using more effective genomic markers [18]. Among parthenogenetic Darevskia, D. rostombekovi was also suggested to be of single origin [32]. In D. armeniaca, four allozyme clones were detected [33], but one rare clone made up the majority of two populations, and another rare clone had different allelic compositions at two loci. ...
... Multiple hybridization events leading to multiple allozyme clones have been described in Cnemidophorus and Heteronotia [34]. The patterns of allozyme variability among species of multiple origins ranged from a large variation (Heteronotia binoei; [6]) to medium (Cnemidophorus tesselatus; [35]), and slight (Darevskia parthenogens; [18,32]) variations. Thus, the patterns of allozyme variation in D. dahli [18] do not contradict the multiple hybridization origin demonstrated in our study, and the higher microsatellite clonal diversity reflects the higher effectiveness of the markers used. ...
The all-female Caucasian rock lizard species Darevskia dahli and other parthenogenetic species of this genus reproduce normally via true parthenogenesis. Previously, the genetic diversity of this species was analyzed using allozymes, mitochondrial DNA, and DNA fingerprint markers. In the present study, variation at three microsatellite loci was studied in 111 specimens of D. dahli from five populations from Armenia, and new information regarding clonal diversity and clone formation in D. dahli was obtained that suggests a multiple hybridization origin. All individuals but one were heterozygous at the loci studied. Based on specific allele combinations, 11 genotypes were identified among the individuals studied. Individuals with the same genotypes formed distinct clonal lineages: one major clone was represented by 72 individuals, an intermediate clone was represented by 21 individuals, and nine other clones were rare and represented by one or several individuals. A new approach based on the detection and comparison of genotype-specific markers formed by combinations of parental-specific markers was developed and used to identify at least three hybridization founder events that resulted in the initial formation of one major and two rare clones. All other clones, including the intermediate and seven rare clones, probably arose through postformation microsatellite mutations of the major clone. This approach can be used to identify hybridization founder events and to study clone formation in other unisexual taxa.
... We found 14 loci with fixed heterozygosity. As suspected, the low variability in L. unisexualis is comparable to that found in L. armeniaca (MHD 0.437– 0.457, MNA 1.46, PLP 45.71; MacCulloch et al, 1995b), L. rostombekovi (MHD 0.424, MNA 1.42, PLP 42.42; MacCulloch et al. 1997 (1979) found that 96% of all skin graft trials were accepted among individuals from five populations of L. unisexualis and concluded that little variation existed. Our populations of L. unisexualis contain three clones indicating a low level of diversity similar to that found other unisexual lacertids (MacCulloch et al. 1995bMacCulloch et al. , 1997 Murphy et al. in press) and in Cnemidophorus neomexicanus (Parker and Selander 1984). ...
... As suspected, the low variability in L. unisexualis is comparable to that found in L. armeniaca (MHD 0.437– 0.457, MNA 1.46, PLP 45.71; MacCulloch et al, 1995b), L. rostombekovi (MHD 0.424, MNA 1.42, PLP 42.42; MacCulloch et al. 1997 (1979) found that 96% of all skin graft trials were accepted among individuals from five populations of L. unisexualis and concluded that little variation existed. Our populations of L. unisexualis contain three clones indicating a low level of diversity similar to that found other unisexual lacertids (MacCulloch et al. 1995bMacCulloch et al. , 1997 Murphy et al. in press) and in Cnemidophorus neomexicanus (Parker and Selander 1984). The variation is much less than that found by Moritz et al. (1989a) in Heteronotia binoei, which probably originated from multiple hybridization events. ...
Protein electrophoresis of Lacerta unisexualis from three populations found that 21 of 36 allozyme loci were homozygous, while 14 expressed fixed heterozygotes and one locus was variable. Three clones were detected at the locus Cat-A. Two individuals represent two rare clones while all others form a common clone. Our favored explanation is the mutation of a preexisting common clone rather than multiple origins.
... Microsatellites are currently widely used in population genetic studies because they are codominant, highly variable and presumably neutral Mendelian markers (Jarne & Lagoda 1996). In a growing number of social insect species microsatellites serve as a useful tool in investigations of social systems (Estoup et al . ...
... The mean repeat number of the longest run of uninterrupted repeats for all loci was 16.9 ± standard deviation (SD) 8.9. We found no general trend for polymorphic loci in P. punctata to consist of longer or uninterrupted repeat motifs than monomorphic loci, as suggested in the literature (reviewed, for example, in Jarne & Lagoda (1996)). All microsatellite sequences are accessible through the EMBL Nucleotide Sequence Database (Accession nos AJ006381-AJ006390). ...
Parthenogenesis is often thought to constitute an evolutionary dead end as compared with sexual reproduction because genetic recombination is limited or nonexistent in parthenogenetic populations. Yet there are many species to demonstrate that parthenogenesis can initially be extremely successful under certain environmental conditions. In this study we used microsatellite markers to investigate the genetic structure of four natural populations of the neotropical thelytokous parthenogenetic ant Platythyrea punctata. Ten dinucleotide microsatellites were isolated from a partial genomic library of P. punctata. Five of these were found to be polymorphic. In a subsequent analysis of 314 workers taken from 51 colonies, we detected low intraspecific levels of variation at all loci, expressed both in the number of alleles detected and heterozygosities observed. Surprisingly, we found almost no differentiation within populations. Populations rather had a clonal structure, with all individuals from all colonies usually sharing the same genotype. Only in one colony from Puerto Rico did some workers have an additional genotype. This low level of genotypic diversity probably reflects the predominance of thelytoky in P. punctata, together with genetic bottlenecks and founder effects. Cross-species amplification of all 10 loci in 29 ant species comprising four different subfamilies yielded positive amplification products in only a limited number of species.
... 7. Facultative parthenogenesis -Parthenogenesis is a mode of asexual reproduction in which female reproduces their offspring without any genetic involvement of a male, e.g., squamate (Snakes and Lizards). Sexually reproducing species like Komodo dragon and several species of snakes are also capable of parthenogenesis in the absence of male partner via mechanism known as half-cloning (a haploid polar body formed due to normal female meiotic divisions fuses with the egg to form a diploid nucleus); this ability is known as facultative parthenogenesis (Ross et al. 1997;Lampert 2008;Laurie and Caldwell 2013). 8. Facultative parental care -According to Kolliker (2007), the survival of offspring totally depend on parental care as offspring cannot survive in the absence of their parents, but there are several animals including insects like N. pustulatus which appear to be facultative in parental care. ...
The facultative trait can be defined as the efficiency of an organism to survive into more than one specific set of environmental conditions which evolves according to a change in the surrounding environment at a particular time.
... Well known purely asexual higher animal taxa are the bdelloid rotifers and ostracod crustaceans (Mark Welch et al., 2009;Schön et al., 2009). Further examples of formally described asexual animal species are some mites (Ros et al., 2008) and lizards (MacCulloch et al., 1997). For example, the lizard Darevskia rostombekowi is obligately parthenogenetic like marbled crayfish. ...
Invasive species are widely recognized as a major threat to biodiversity and non-indigenous crayfish species (NICS) figure among the main threats to freshwater environments, biodiversity and ecosystem functioning. The main vector for freshwater crayfish introduction is the aquaculture and the pet trade and 28 NICS are known so far, distributed worldwide, except for Antarctica. Procambarus clarkii, P. fallax, Cherax quadricarinatus, C. destructor and C. canii figure as the most frequently introduced, widespread species and to which great impact is associated. Habitat degradation, transmission of diseases, modification of food webs, predation on native species and competition for resources are the most recurrent threats associated to the establishment of NICS and the main efforts to control this species involve the elimination or reduction of populations through mechanical, chemical or biological methods although only few examples of success exist. This chapter summarizes the major information on NICS, including their distribution, impacts on biodiversity and management possibilities.
... Genetic variation, which may post-date the time of the initial hybridogenesis event, was however found in most investigated species. The lacertid Darevskia (Lacerta) rostombekowi had until recently been thought to represent a monoclonal lineage with no variation in allozyme markers [248]. However, a study using microsatellite loci has recently shown that post-formation genomic variation also exists in this species [249]. ...
In this contribution, the aspects of reptile and amphibian speciation that emerged from research performed over the past decade are reviewed. First, this study assesses how patterns and processes of speciation depend on knowing the taxonomy of the group in question, and discuss how integrative taxonomy has contributed to speciation research in these groups. This study then reviews the research on different aspects of speciation in reptiles and amphibians, including biogeography and climatic niches, ecological speciation, the relationship between speciation rates and phenotypic traits, and genetics and genomics. Further, several case studies of speciation in reptiles and amphibians that exemplify many of these themes are discussed. These include studies of integrative taxonomy and biogeography in South American lizards, ecological speciation in European salamanders, speciation and phenotypic evolution in frogs and lizards. The final case study combines genomics and biogeography in tortoises. The field of amphibian and reptile speciation research has steadily moved forward from the assessment of geographic and ecological aspects, to incorporating other dimensions of speciation, such as genetic mechanisms and evolutionary forces. A higher degree of integration among all these dimensions emerges as a goal for future research.
... True parthenogenesis in vertebrates is found only within squamate reptiles (e.g., lizards, snakes and amphisbaenians; Fujita and Moritz, 2009). Accumulated data indicate that most parthenogens originated from multiple recent hybridization events between closely related bisexual species (MacCulloch et al., 1997;Fujita and Moritz, 2009;Kearney et al., 2009;Freitas et al., 2016). Nonetheless, there is one well-documented exception, in which a case of two spontaneous origins was found in Xantusiidae lizards (Sinclair et al., 2010). ...
In vertebrates, true parthenogenesis is found only in squamate reptiles and (mostly) originates via interspecific hybridization after secondary contact. In many cases, parthenogenesis is followed by an increase of ploidy, resulting in triploid lineages. Phylogenetic analyses derived from nuclear and maternally inherited markers can help to clarify the mechanisms of origin and the potential parental species involved. In the Amazon region, parthenogenetic lizards of the Loxopholis percarinatum complex are widely distributed, comprising both diploid and triploid clones. Recently, putative males of L. percarinatum were reported, suggesting the existence of bisexual populations based on morphological data. Here, we used mitochondrial and nuclear data to investigate the origin of parthenogenesis in Loxopholis. Mitochondrial DNA analysis revealed three major lineages: unisexual/2n, unisexual/3n and bisexual, the last of which comprised two sub-lineages placed as the sister taxon to the unisexual/3n lineage. Genetic divergence among the lineages was ∼10% but was lower between the unisexual/3n and bisexual lineages (∼6%). Both mtDNA and nuDNA indicated that individuals from the bisexual lineages might belong to a new species. Nuclear DNA evidence indicates that crossings occasionally occur between unisexual 2n and males from the new bisexual species. Phylogenetic analysis of nuDNA showed L. ferreirai as the closest described bisexual species to the complex. Our results revealed an ancient origin of parthenogenesis in the L. percarinatum complex, in contrast to most young (Pleistocene) parthenogenetic lizards described thus far. Two hybridization events seem to have been involved: the first event occurred in late Miocene, between the ancestral lineage (“A”) of the new bisexual species (as a maternal species) and the ancestral lineage of L. ferreirai, as a paternal species of L. percarinatum 2n; and the second event occurred in Pliocene-Pleistocene, in a backcross between L. percarinatum 2n and a male from the common ancestor (“B”) of the new bisexual species giving rise to the lineage of L. percarinatum 3n. With these results, we showed that L. percarinatum complex also includes, at least, one undescribed bisexual species in addition to the two known parthenogenetic lineages (2n and 3n). Finally, we present evidence that diploid individuals of L. percarinatum experienced an event of wide demographic expansion over the past million years under an allele surfing model.
... Well known purely asexual higher animal taxa are the bdelloid rotifers and ostracod crustaceans (Mark Welch et al., 2009;Schön et al., 2009). Further examples of formally described asexual animal species are some mites (Ros et al., 2008) and lizards (MacCulloch et al., 1997). For example, the lizard Darevskia rostombekowi is obligately parthenogenetic and monoclonal like marbled crayfish. ...
The marbled crayfish is the only obligately parthenogenetic decapod crustacean and a novel research model and invasive animal on three continents. It is regarded either as a parthenogenetic form of slough crayfish Procambarus fallax or as a separate species named Procambarus virginalis . In order to investigate the species question of this unusual crayfish in detail we have identified the similarities and differences in morphology, life history, genetics, behaviour, ecology and biogeography between marbled crayfish and P. fallax . We have investigated specimens from natural habitats, laboratory colonies and museum collections and performed a meta-analysis of our data and published data. Our COI based molecular tree with 27 Cambaridae confirms closest relationship of marbled crayfish with P. fallax . Marbled crayfish and P. fallax are similar with respect to morphological characters, coloration and body proportions, but differ considerably with respect to body size, fertility and longevity. The mitochondrial genes of both crayfish are similar, but some nuclear genomic features are markedly different. Both crayfish are eurytopic and have two major annual recruitment periods, but marbled crayfish show different population structure and higher invasiveness. Marbled crayfish occur in boreal to tropical habitats of Europe, Madagascar and Japan, but P. fallax is confined to the subtropics and tropics of the southeastern USA. Laboratory experiments suggest reproductive isolation of both crayfish. The application of the Evolutionary Genetic Species Concept for asexuals to all available data supports raising marbled crayfish from "forma" to species rank. A determination key is provided to discriminate Procambarus virginalis , the first asexual decapod species, from its most likely parent species P. fallax .
... Biogeographic studies showed that the living range of D. rostombekovi lizards is relatively small and includes isolated populations from North Armenia and the adjacent territories of Azerbaijan, as well as an isolated high-mountain population on the southwest shores of Lake Sevan (near the Zagalu settlement). Allozyme analysis of various D. rostombekovi populations (with the exception of the Zagalu population) did not reveal any allozyme variability, and this led to the idea that the monoclonal genetic structure of the spe- cies [8] is different from that of the parthenogenetic species D. dahli, D. armeniaca, and D. unisexualis composed of two to five allozyme clones [9]. Genetic homogeneity of D. rostombekovi populations revealed by allozyme analysis contradicted the results of morphological studies that revealed considerable differences between the populations [3]. ...
Assessment of genetic diversity of unisexual (parthenogenetic) species of vertebrates is among the major objectives of research in these species. Various nuclear or mitochondrial genome markers can be used for such an assessment. Microsatellite DNAs are among the most efficient genetic markers, since the mutation rate in these fragments is high. Identification and characterization of such markers are the basic stages of genetic research in parthenogenetic species. Allelic polymorphism of three microsatellite loci in populations of the parthenogenetic species Darevskia rostombekovi (n = 42) and bisexual parent species D. raddei (n = 6) and D. portschinskii (n = 6) has been assessed by locus-specific PCR for the first time. All representatives of the parthenogenetic species D. rostombekovi used in the present study turned out to be heterozygous. The number of alleles of the different loci ranged from two to five in the populations investigated. The nucleotide sequence of the allelic variants of the loci investigated has been determined. The differences between the alleles were apparently related to variation in the structure of microsatellite clusters and single-nucleotide substitutions in DNA fragments located in the vicinity of the clusters at fixed distances from the latter. Structural variants of the alleles formed allele-specific haplotype markers that were inherited from the bisexual parent species. The origin (inheritance from the maternal or paternal species) has been determined for each allele of the parthenogenetic species. The distribution, frequency of occurrence, and pattern of combination of the alleles of microsatellite loci in D. rostombekovi populations have been characterized; these features determined the identity of each population. The data obtained can be used for assessment of the clonal diversity of the parthenogenetic species D. rostombekovi and the identification of a possible scenario of the emergence of the diversity in the populations.
... Hybridization between Anolis trinitatis and A. aeneus (18%; Dactyloidae) showed that the reproductive function was affected and thus the backcross hybrids were rare in nature (Gorman et al., 1971). Nevertheless, the fertile hybrids of the species pairs exhibiting comparable genetic distances were also repeatedly detected in nature: e.g., Podarcis sicula and P. melisellensis (18%), P. sicula and P. wagleriana (17%; Gorman et al., 1975; Capula, 1993), Darevkia saxicola and D. brauneri (18%; Lacertidae; MacCulloch et al., 1997; for review see Fu, 1999; Murphy et al., 2000). ...
Animal species are delimited by reproductive isolation mechanisms (RIMs). Postzygotic RIMs are mainly products of genetic differences and thus their strength increases with elapsed divergence time. The relationship between postzygotic reproductive isolation and genetic divergence, however, differs considerably among major clades of vertebrates. We reviewed the available literature providing empirical evidence of natural and/or experimental hybridization between distinct species of lizards (squamates except snakes). We found that hybridization events are widely distributed among nearly all major lizard clades. The majority of research focuses on parthenogenetic species and/or polyploid hybrids in families Lacertidae, Teiidae and Gekkonidae. Homoploid bisexual hybrids are mainly reported within Lacertidae and Iguania groups. As a proxy of genetic divergence of the hybridizing taxa we adopted nucleotide sequence distance (HKY85) of mitochondrial cyt b gene. The upper limit of genetic divergence was similar with regard to both parthenogenetic and bisexual hybrids. Maximum values of these distances between hybridizing species of lizards approached 18%-21%, which is comparable to or even exceeds the corresponding values reported for other principal clades of vertebrates. In spite of this, F-1 hybrids are typically at least partially fertile in lizards and thus genetic introgression between highly divergent species is possible. The relationship between the genetic distance and hybrid fertility was not found
... Bobyn et al. (1996) and considered D. nairensis conspecific with D. raddei based on allozyme and mitochondrial DNA data, respectively. Using allozymes in combination with mitochondrial DNA (mtDNA) data, four sexual species, D. raddei, D. mixta, D. valentini and D. portschinskii, were identified as the parental species of the seven currently known unisexual species, which originated from interspecific hybridization ( Fig. 1; Moritz et al., 1992a;MacCulloch et al., 1995bMacCulloch et al., , 1997cMurphy et al., 1997;Fu, Murphy & Darevsky, 1999a;Fu et al., 1998). Furthermore, mitochondrial DNA data revealed that the hybridization between D. raddei and D. valentini occurred at least two times, which led to the formation of two distinctive unisexual lineages, D. unisexualis-D. ...
A phylogeny of Caucasian rock lizards (genus Darevskia, formerly Lacerta) was reconstructed using mitochondrial DNA sequence and allozyme data. All 15 bisexual species grouped into three major clades: thecaucasica, saxicola and rudis clades. Unisexual Darevskia originate from inter-clade hybridization, never from within clades. Only two clades, the caucasica clade and the rudis clade, were involved in forming unisexuals; the saxicola clade was never involved. Furthermore, the hybridization is directional in that thecaucasica clade contributed only maternal parents and the rudis clade only paternal parents. The formation of unisexual species is best explained by sexually directional phylogenetic constraints. We hypothesize that the causative agents are likely to be genes linked with the sex chromosomes within the parental sexual species.
... Avise et al., 1991). To pick just a few examples, the diploid parthenogenetic rock lizard Darevskia rostombekovi of central Europe apparently arose via a single cross between a sexual D. raddei female and a sexual D. portschinskii male (Moritz, Wright & Brown, 1992;MacCulloch et al., 1997), whereas some other unisexual taxa such as parthenogenetic lizards Menetia greyii (Adams et al., 2003) and hybridogenetic fishes named Poeciliopsis monachalucida (Quattro, Avise & Vrijenhoek, 1991) each encompass multiple evolutionary lineages that originated via separate hybridization events. In the Poeciliopsis case, the hybridizations that give rise to unisexual biotypes appear to be ongoing. ...
I love the term ‘natural history’ because it encapsulates the sentiment that nature's operations have evolutionary etiologies. Charles Darwin was a natural historian par excellence and his elucidation of natural selection, artificial selection, and sexual selection fundamentally changed how scientists interpret the origins of biological features previously ascribed to sentient craftsmanship by supernatural agents. Darwin's insights on evolutionary forces grew from his exceptional knowledge of natural history, yet two key topics steeped in natural history – sex and reproductive genetics – remained poorly understood (and probably even shunned) in Darwin's Victorian era. That situation changed dramatically in the latter half of the 20th century with societal awakenings about sexuality that also happened to coincide with the introduction of molecular parentage analyses that unveiled a plethora of formerly hidden ‘sexcapades’ throughout the biological world. Here I summarize some of the evolutionary revelations that have emerged from selection theory as applied to genetic and phylogenetic information on clonality, hermaphroditism, and pregnancy, three procreative phenomena that are relatively rare in vertebrate animals and thus offer alternative evolutionary perspectives on standard reproductive modes. Collectively, these three peculiarities of nature illustrate how the abnormal in biology can enlighten evolutionary thought about the norm.
... Multiple genetic studies, based on the both allozyme and molecular genetic traits suggest that each parthenogenetic form is descending from very few hybrid clones. An extreme case is "rostombekovi," which appears to descend from a single clone (MacCulloch et al., 1997b). No variation in mitochondrial haplotypes were recorded in parthenogenetic forms, whose maternal species is D. mixta: dahli and armeniaca (Fu et al., 1999). ...
Given sufficient time and limited gene flow, evolutionary lineages tend to transform into separate species. Mechanisms preventing assimilation during repeated gene-flow events include divergent adaptations and the development of pre-or postzygotic isolation. We analysed the morphological and genetic boundaries of three species of the rock lizard clade Darevskia 'rudis' (Darevskia rudis, Darevskia valentini, and Darevskia portschinskii) in relation to the environment, and tried to reconstruct evolutionary pathways underlying the observed separation among the species. We studied the geographic distribution of the scalation traits, microsatellite genotypes, and mitochondrial haplotypes. Our analyses showed consistent morphological and genetic patterns at the centre of the ranges for each species, but asymmetric distribution of alleles and scalation characters within the current contact zones among the species. The genetic and morphological diversification of the clade has been shaped during glacial isolation in an area of Southern Caucasus, away from the Black Sea Coast. The ancestral lineage of D. portschinskii separated from the common D. rudis–D. valentini lineage in the middle Pleistocene, and the two latter lineages separated in relatively recent geological time. Neither of the lineages attained complete lineage sorting; moreover, isolation and migration modelling have helped to detect recombinant gene flow from D. rudis to D. portschinskii (but not to D. valentini). This is most likely linked with climatically more similar suitable habitats between D. rudis and D. portschinskii than between D. valentini and the other two species. In itself, the isolation period was insufficient for the development of intrinsic isolation mechanisms in the system studied. Thus, differential landscape-dependent selection within the contact zones is likely to have triggered the rapid development of isolation mechanisms.
... Seven parthenogenetic species of Caucasian rock lizard have been described to date. The genetic variation within these lizard species has recently been subjected to detailed investigations by means of allozyme electrophoresis and mtDNA study (Moritz et al., 1992; MacCulloch et al., 1995b MacCulloch et al., , 1997 Murphy et al., 1997; Fu et al., 1998; Fu, 1999). All but one species showed a similar pattern, in that each species consists of one common, widespread clone and a few rare clones. ...
Clonal variation in Lacerta armeniaca was investigated using allozyme electrophoresi s and morphol-ogy. Among the 35 allozyme loci examined, three were variable, which divided L. armeniaca into four clones. One rare clone of L. armeniaca made up the majority of two populations. This contrasts to rare clones in other parthenogeneti c Caucasian rock lizards which typically consist of only one or two individuals. Another rare clone, which showed a striking colouration difference, had different allelic composition at two loci. Although mutation is a possible explanation of the origin of the clonal variation, the alternative, multiple origin, is equally likely.
... Bobyn et al. (1996) and considered D. nairensis conspecific with D. raddei based on allozyme and mitochondrial DNA data, respectively. Using allozymes in combination with mitochondrial DNA (mtDNA) data, four sexual species, D. raddei, D. mixta, D. valentini and D. portschinskii, were identified as the parental species of the seven currently known unisexual species, which originated from interspecific hybridization (Fig. 1; Moritz et al., 1992a; MacCulloch et al., 1995b MacCulloch et al., , 1997c Murphy et al., 1997; Fu, Murphy & Darevsky, 1999a; Fu et al., 1998, in press). Furthermore, mitochondrial DNA data revealed that the hybridization between D. raddei and D. valentini occurred at least two times, which led to the formation of two distinctive unisexual lineages, D. unisexualis—D. ...
A phylogeny of Caucasian rock lizards (genus Darevskia, formerly Lacerta) was reconstructed using mitochondrial DNA sequence and allozyme data. All 15 bisexual species grouped into three major clades: the caucasica, saxicola and rudis clades. Unisexual Darevskia originate from inter-clade hybridization, never from within clades. Only two clades, the caucasica clade and the rudis clade, were involved in forming unisexuals; the saxicola clade was never involved. Furthermore, the hybridization is directional in that the caucasica clade contributed only maternal parents and the rudis clade only paternal parents. The formation of unisexual species is best explained by sexually directional phylogenetic constraints. We hypothesize that the causative agents are likely to be genes linked with the sex chromosomes within the parental sexual species.
... 1 Date adapted from MacCulloch et al. (1995b) and Fu et al. (2000). 2 Data adapted from Murphy et al. (1997). 3 Data adapted from MacCulloch et al. (1997) ...
Allozyme electrophoresis of four sibling parthenogenetic Caucasian rock lizards Darevskia unisexualis, D.uzzelli, D.sapphirina, and D.bendimahiensis found seven clones and five variable loci. The data supported the hypothesis that D.raddei and D.valentini are the parental species of all four parthenogens. Variation patterns in Darevskia were summarized. Species that originated from a single F1 typically consisted of one widespread clone with a few rare clones. Species with multiple origins displayed variation only
slightly higher than species with a single origin. This is contrary to other genera of parthenogenetic lizards, in which cases
massive clonal variations were observed.
... Additional field and laboratory studies are necessary to determine the influence of environmental conditions on male occurrence and to clarify its role in a population dominated by hermaphrodites. Moreover, the origin of R. marmoratus is not clearly understood, thus, its unique means of self-fertilization and reproduction may be a result of hybridization between two other species of Rivulus which have evolved rapidly, like the parthenogenetic teiid lizards of the North American Great Basin and the lacertid lizards of the Amazon, and the gynogenic Poecilia formosa from P. latipinna and P. mexicana crosses (Billy & Crews 1986, Ryan et al. 1996, MacCulloch et al. 1997, Murphy et al. 2000. ...
We compared life-history traits such as fecundity, sex ratio, reproductive cycle, age at sexual maturity, embryonic period, egg size, early growth and morphology in two clonal strains (PAN-RS and DAN) of the mangrove killifish, Rivulus marmoratus, under constant rearing conditions. We found a positive relationship between growth and reproductive effort. Fecundity was significantly higher in the PAN-RS strain than in the DAN strain. The sex ratio was significantly different, with DAN producing more primary males than PAN-RS. Spawning and ovulation cycle did not clearly differ between the strains. PAN-RS showed a significantly higher growth rate than DAN from 0 to 100days after hatching, however, age at sexual maturity, embryonic period, egg size, and morphometric and meristic characteristics (vertebral and fin-ray counts) did not differ between the two strains. The high fecundity of PAN-RS may provide an increased chance of offspring survival, while the attainment of sexual maturity at a smaller size in DAN may allow them to invest earlier in reproduction to increase breeding success. Variations in the life-history traits of PAN-RS and DAN may be adaptive strategies for life in their natural habitat, which consists of mangrove estuaries with a highly variable environment.
... 1. tially higher clonal diversity and differentiation of partenogenetic lizards regarding mini-and microsatellite loci, when compared to allozyme loci (Table 2) and (or) especially to the loci controlling the skin pattern and color. It was shown that variability levels of partenogenetic species with respect to the skin color and pattern, allozyme loci, histocompatibility, and finally, nuclear DNA markers cannot be compared [8, 19,383940. If clonal diversity is estimated in respect to each system of morphological and genetic characters, then partenogenetic lizards of the genus Darevskia should be considered as a multiclonal species system. ...
Population and family samples of two morphological forms (mutant and normal with respect to dorsal color) of parthenogenetic lizard species Darevskia armeniaca were examined by means of DNA fingerprinting using M13 mini- and (GACA)
n
and (TCC)
n
microsatellite DNA markers. The morphological forms examined were characterized by clonally inherited, species-specific patterns of the DNA markers, which were different from the species-specific DNA fingerprints of the other parthenogenetic species of the genus Darevskia (D. dahli, D. unisexualis, and D. rostombekovi). The mean index of similarity (S) obtained for a sample of 36 individuals from three isolated populations using three types of DNA markers was 0.966. This was similar to those observed in D. dahli (0.962) (P > 0.05), but higher than that in D. unisexualis (0.950) (P < 0.05)="" and="">D. rostombekovi(0.875) (P < 0.01).="" inheritance="" of="" m13="" minisatellite="" and="">
n
microsatellite DNA markers in the F1 offspring of parthenogenetic lizards was examined. It was shown that variability and clonal diversity of the fingerprint phenotypes observed in the populations and families of D. armeniaca could be at least partly explained by RFLP mutations in microsatellite repeats.
... Seven diploid all-female species are currently known, all from the Caucasus Mountains of Armenia [1,5,6]. Previous studies on these parthenogenetic species revealed some degree of allozyme variation7891011 and low variability of mitochondrial DNA [12]. However multilocus DNA fingerprinting revealed very high levels of genetic variation in parthenogenetic populations of Darevskia unisexualis, D. armeniaca, D. dahli and D. rostombecovi13141516. ...
Unisexual all-female lizards of the genus Darevskia that are well adapted to various habitats are known to reproduce normally by true parthenogenesis. Although they consist of unisexual lineages and lack effective genetic recombination, they are characterized by some level of genetic polymorphism. To reveal the mutational contribution to overall genetic variability, the most straightforward and conclusive way is the direct detection of mutation events in pedigree genotyping. Earlier we selected from genomic library of D. unisexualis two polymorphic microsatellite containing loci Du281 and Du215. In this study, these two loci were analyzed to detect possible de novo mutations in 168 parthenogenetic offspring of 49 D. unisexualis mothers and in 147 offspring of 50 D. armeniaca mothers. No mutant alleles were detected in D. armeniaca offspring at both loci, and in D. unisexualis offspring at the Du215 locus. There were a total of seven mutational events in the germ lines of four of the 49 D. unisexualis mothers at the Du281 locus, yielding the mutation rate of 0.1428 events per germ line tissue. Sequencing of the mutant alleles has shown that most mutations occur via deletion or insertion of single microsatellite repeat being identical in all offspring of the family. This indicates that such mutations emerge at the early stages of embryogenesis. In this study we characterized single highly unstable (GATA)(n) containing locus in parthenogenetic lizard species D. unisexualis. Besides, we characterized various types of mutant alleles of this locus found in the D. unisexualis offspring of the first generation. Our data has shown that microsatellite mutations at highly unstable loci can make a significant contribution to population variability of parthenogenetic lizards.
Caucasian rock lizards of the genus is a unique taxa, including both bisexual and parthenogenetic species. The parthenogenetic species have originated as a result of natural hybridisation between females and males of different bisexual species. The species involved in interspecific hybridisation are called parental. However, sympatric zones (SZ) of unisexual and bisexual rock lizards of the Caucasus are still poorly studied, although they are very important for understanding the role of hybrid individuals of different origin in reticulate evolution. This paper presents the location of the SZs of parthenogenetic and
their parental bisexual rock lizards of the genus Darevskia in Armenia and adjacent territories of Georgia and Nagorno-Karabakh. We summarised the locations of the SZs identified from 1957 to the present, based on our field survey data gathered in 2018-2019and records from publications and museum collections. This dataset includes 39 SZs of three types: SZ of parental bisexual species, SZ of parental species with unisexual species and SZ of the parthenogenetic species. For each zone, species composition, geographical and altitudinal distribution are presented. New records expand our knowledge of the geographical and altitudinal distribution of SZs in these species and provide additional data for understanding the mechanisms of reticulate evolution and hybridogeneous speciation in the past, present and future.
A bibliography zoologist, evolutionist and biogeography Ilya Sergeyevich Darevsky (1924–2009), which includes 466 names. Time publications scientist covers the period from 1938 to 2014.
About 99.9% of vertebrate species reproduce sexually. This makes the exceptional 0.1%-the asexual or clonal reproducers-fascinating in their own right, and also uniquely instructive about the biological significance of alternative reproductive modes. This book describes the genetics, ecology, natural history, and evolution of all of the world's approximately 100 "species" of vertebrate animal that routinely display one form or another of clonal or quasi-clonal reproduction. The book investigates the astounding realm of sexual abstinence, from the levels of DNA molecules and somatic cells to whole animals and natural populations. Also described is how scientists have learned to mimic and extend nature's own clonal processes by engineering perfect copies of genes, genomes, and whole animals in the laboratory. By considering the many facets of sexual abstinence and clonal reproduction in vertebrate animals, new light is also shed on the biological meaning and ramifications of standard sexuality.
Leposoma percarinatum is one of the two recognized parthenogenetic species in the lizard family Gymnophthalmidae, and only females have been reported to date. Here we report and describe the first known males attributed to the species from two localities of northwestern Amazonia. We compare the morphological variation (15 meristic and 10 discrete characters, all relevant to species identification in Leposoma) of males and females from these populations with that of specimens from unisexual populations to test the hypothesis that they belong to the same species. We did not find significant morphological differences between unisexual and bisexual populations, except for those associated with sexual dimorphism. Additionally, we reviewed literature dealing with the origin of parthenogenesis in L. percarinatum and we provide some insights into this subject, in view of the discovery of males in this species.
Resumo. Leposoma percarinatum é uma das duas espécies de lagartos partenogenéticas da familia Gymnophthalmidae, onde apenas fêmeas são conhecidas até o momento. Neste artigo reportamos e descrevemos os primeiros machos encontrados da espécie, pertencentes a duas populações no noroeste da América do Sul. Com o intuito de testar a hipótese de que os machos encontrados pertencem à espécie L. perca‑ rinatum, comparamos a variação morfológica (15 caracteres merísticos e 10 categóricos, todos relevantes para a identificação de espécies do gênero Leposoma) encontrada em machos e fêmeas das duas populações bissexuais com exemplares de populações unissexuais ao longo da Amazônia. Não encontramos diferenças significativas na morfologia entre populações uni e bissexuais, a não ser aquelas decorrentes de dimorfismo sexual tradicionalmente conhecidas em lagartos. Adicionalmente, revisamos a literatura referente à origem da partenogênese em L. percarinatum e fornecemos algumas reflexões sobre este tópico, fruto do aparecimento de machos na espécie.
There are a number of intriguing exceptions and variations to the classical rule that the sperm and ovum share equal parentage in a diploid zygote. There is an enormous diversity of organismal life cycles that do not involve cell fusion at all (e.g., those of bacteria) or that involve fusion of isogamous gametes rather than sperm and ova. This chapter focuses particularly on unusual systems that are derived from the classical sperm-egg fusion system that is so familiar. It considers systems in which the parentage of diploid offspring is not shared equally between the sperm and the egg but instead is monopolized by one or the other. It discusses the potential for sperm-egg and sperm-female conflict under such genetic systems and considers whether these conflicts have affected the evolution of sperm in some lineages. Furthermore, it discusses the unusual case of endosperm development in angiosperms, in which sperm fuse with non-egg cells to establish purely somatic cell lineages, and some analogous cases of somatic tissues in insects that develop from polar bodies.
The phylogeny of 12 species of Caucasian rock lizards and ground lizards, genus Lacerta, subgenus Archaeolacerta, was determined from allozyme data. Three additional species of Lacerta formed the outgroup. Of the 35 loci resolved, 20 were phylogenetically informative. Permutation tail probabilities calculated using Hennig86 and RandomCladistics and g1 statistics obtained in PAUP revealed significant pattern in the data. Our analysis resolved 12 most parsimonious trees, among which were three well-supported monophyletic groups: 1) (Lacerta alpina, L. caucasica, L. daghestanica) [the L. caucasica group]; 2) (L. mixta, L. saxicola, L. raddei-nairensis) [the L. saxicola group]; and 3) (L. parvula, L. portschinskii (L. valentini, L. rudis)) [the L. rudis group]. The second and third groups formed a clade. The ground lizards L. praticola and L. derjugini were resolved as ingroup members, but their placement in the globally most parsimonious trees was ambiguous. A preferred tree was chosen by alternately pruning L. praticola and L. derjugini from the tree. In doing so, L. praticola was resolved as the sister taxon of the L. caucasica group, and L. derjugini was resolved as the sister taxon of the clade containing the L. saxicola and L. rudis groups. Our results are somewhat congruent with the morphology-based phylogeny of Darevsky (1967).
A bibliography zoologist, evolutionist and biogeography Ilya Sergeyevich Darevsky (1924–2009), which includes 466 names. Time publications scientist covers the period from 1938 to 2014.
According to kin selection theory, competition among monoclonal animals must be lower than between unrelated individuals. Thus, we propose that home range and core area overlap in parthenogenetic lizards will be broader than female range overlap in similar gonochoristic species. To test this hypothesis, we examined home range locations and space use of parthenogenetic Armenian Rock Lizards (Darevskia armeniaca) and compared them with home range locations and space use of gonochoristic species. We demonstrated that parthenogenetic Rock Lizards have a total range structure typical of insectivorous lizards, consisting of a sally zone, a home range, and one or more core areas. Some core areas contained activity centers, associated strongly with key basking sites and shelters. Provisional residents were found within the same range for 1 or 2 years, whereas wanderers visited study sites for 1 or 2 weeks per season. Settlement structure varied greatly among years. Home ranges, core areas, and even activity centers and basking sites of parthenogenetic females overlapped extensively, unlike in females of nonparthenogenic species. Monoclonal origins and high level of relatedness within unisexual species are possible explanations of the extended range overlap among parthenogenetic females.
INEICH I., 2013 - Analyse d'ouvrage – "The Snakes of the Lesser Sunda Islands (Nusa Tenggara), Indonesia", par Ruud DE LANG. 2011. Edition Chimaira, Frankfurt am Main, Frankfurt Contributions to Natural History, volume 47, 359 pages. Bulletin de la Société Herpétologique de France, 144: 194-198.
INEICH I., 2013 - Analyse d'ouvrage – "Herpetofauna of Armenia and Nagorno-Karabakh", par Marine S. ARAKELYAN, Felix D. DANIELYAN, Claudia CORTI, Roberto SINDACO et Alan E. LEVITON. 2011. Society for the Study of Amphibians and Reptiles, Contributions to Herpetology, volume 27, 149 pages. Bulletin de la Société Herpétologique de France, 144: 183-188.
INEICH I., 2013 - Analyse d'ouvrage – "Reproductive Biology and Phylogeny of Snakes", par Robert D. ALDRIDGE et David M. SEVER (eds.). 2011. Science Publishers & CRC Press, Taylor & Francis Group, 759 pages. Bulletin de la Société Herpétologique de France, 144: 167-170.
INEICH I., 2013 - Analyse d'ouvrage – "The eponym dictionary of reptiles", par Bo BEOLENS, Michael WATKINS et Michael GRAYSON. 2011. The John Hopkins University Press, Baltimore, Maryland, USA, 296 pages. Bulletin de la Société Herpétologique de France, 144: 161-163.
INEICH I., 2013 - Analyse d'ouvrage – "A Contribution to the Herpetology of Northern Pakistan : The Amphibians and Reptiles of Margalla Hills National Park and Surrounding Regions", par Rafaqat MASROOR. 2012. Society for the Study of Amphibians and Reptiles, Contributions to Herpetology, volume 28 et Edition Chimaira, Frankfurt am Main, Frankfurt Contributions to Natural History, volume 52, 217 pages. Bulletin de la Société Herpétologique de France, 144: 189-193.
INEICH I., 2013 - Analyse d'ouvrage – "Die Amphibien und Reptilien Bulgariens", par Andrei STOJANOV, Nikolay TZANKOV et Borislav NAUMOV. 2011. Edition Chimaira, Frankfurt Contributions to Natural History volume 35, 588 pages. Bulletin de la Société Herpétologique de France, 144: 179-182.
Le serpent Natricidae Natrix tessellata (Lauren-ti, 1768) est une espèce aquatique à vaste répar-tition occupant trois continents, l'Europe, l'Afrique et l'Asie. Elle se rencontre en effet depuis la Suisse et l'Allemagne en Europe cen-trale jusqu'en Égypte sur le continent africain et à l'est jusqu'à la Province du Xinjiang en Chine. L'espèce occupe une diversité d'habitats, depuis les oasis des déserts de Jordanie, de Syrie ou d'Iran jusqu'en pleine mer en Méditerranée ou en Mer Noire, à des altitudes inférieures au niveau de la mer sur les berges de la Mer Cas-pienne jusqu'au-dessus de 2 800 m dans certai-nes vallées, en passant par les steppes d'Asie centrale ou encore le coeur de certaines grandes cités modernes comme Prague ou Bucarest. Malgré cela, nos connaissances sur cette espèce, au régime principalement piscivore, restaient éparses et marginales. Ce volume, publié dans la série Mertensiella associée à la magnifique revue allemande Salamandra (tous deux édités par la DHGT, Société allemande d'Herpétologie), dresse un état actualisé des connaissances à présent conséquentes sur l'espèce, aussi bien sa biologie, sa répartition et son écologie, que des problèmes liés à sa conservation. Il s'agit là d'un ouvrage collectif qui regroupe 57 arti-cles et un DVD impliquant un total de 122 auteurs et co-auteurs issus de plus de 22 pays. Dans l'introduction, l'éditeur de ce volume, l'herpétologue suisse Konrad Mebert, expose la laborieuse genèse de son exploit éditorial totalisant plus de 4 000 heures de travail réparties sur quatre années. Il propose à présent un produit final d'excellente qualité. Ce dernier regroupe des articles presque tous en anglais émanant des quatre coins de la vaste aire de répartition du serpent, nous donnant ainsi une vision de la plasticité d'un taxon (habitat, éco-logie, comportement, morphologie etc.) qui reste malgré tout une espèce à part entière. En dépit de quelques variations locales et régionales, une couleuvre tessellée d'Italie n'est guère
Le serpent Natricidae Natrix tessellata (Lauren-ti, 1768) est une espèce aquatique à vaste répartition occupant trois continents, l'Europe, l'Afrique et l'Asie. Elle se rencontre en effet depuis la Suisse et l'Allemagne en Europe centrale jusqu'en Égypte sur le continent africain et à l'est jusqu'à la Province du Xinjiang en Chine. L'espèce occupe une diversité d'habitats, depuis les oasis des déserts de Jordanie, de Syrie ou d'Iran jusqu'en pleine mer en Méditerranée ou en Mer Noire, à des altitudes inférieures au niveau de la mer sur les berges de la Mer Cas-pienne jusqu'au-dessus de 2 800 m dans certai-nes vallées, en passant par les steppes d'Asie centrale ou encore le coeur de certaines grandes cités modernes comme Prague ou Bucarest. Malgré cela, nos connaissances sur cette espèce, au régime principalement piscivore, restaient éparses et marginales. Ce volume, publié dans la série Mertensiella associée à la magnifique revue allemande Salamandra (tous deux édités par la DHGT, Société allemande d'Herpétologie), dresse un état actualisé des connaissances à présent conséquentes sur l'espèce, aussi bien sa biologie, sa répartition et son écologie, que des problèmes liés à sa conservation. Il s'agit là d'un ouvrage collectif qui regroupe 57 arti-cles et un DVD impliquant un total de 122 auteurs et co-auteurs issus de plus de 22 pays. Dans l'introduction, l'éditeur de ce volume, l'herpétologue suisse Konrad Mebert, expose la laborieuse genèse de son exploit éditorial totalisant plus de 4 000 heures de travail réparties sur quatre années. Il propose à présent un produit final d'excellente qualité. Ce dernier regroupe des articles presque tous en anglais émanant des quatre coins de la vaste aire de répartition du serpent, nous donnant ainsi une vision de la plasticité d'un taxon (habitat, éco-logie, comportement, morphologie etc.) qui reste malgré tout une espèce à part entière. En dépit de quelques variations locales et régionales, une couleuvre tessellée d'Italie n'est guère...
Allozyme variation at 35 gene loci is investigated in 161 specimens of the uniparental Caucasian lizard Lacerta dahli from
several locations in Armenia and Georgia. All individuals are heterozygotic at 12 loci, and homozygotic at 21 loci. Variation
at two loci results in five uniparental clones. One clone is widespread whereas four are geographically restricted and are
represented by only one or two individuals. Because successful formation of uniparental clones is rare, and because the biparental
species forming them are now allopatric, the most probable explanation for the origin of the observed clonal diversity is
either mutation or recombination within the common clone. The rare clones have lower levels of enzyme activity at four loci,
suggesting that these organisms may be genetically deficient. Although the evidence points to change in a pre-existing clone,
the possibility of multiple origins cannot be ruled out.
Genetic diversity at 37 allozyme loci was surveyed in Lacerta portschinskii from contiguous populations and from a disjunct
population. Indices of genetic diversity (heterozygosity, number of alleles per locus, and percentage of loci polymorphic)
were greater in contiguous populations than in the smaller disjunct population. In this regard, disjunct populations appear
to be similar to island populations. Indices of genetic diversity in Caucasian Lacerta are less than those reported from vagile
lizard taxa and more similar to those of sit-and-wait predators.
The interaction of locally perfused cholecystokinin-8 (sulphated) with systemically administered apomorphine was studied on the release of dopamine and its metabolites using microdialysis in the neostriatum of the halothane-anaesthetized male rat. Dialysate levels of dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid were assayed by high performance liquid chromatography in combination with electrochemical detection. Perfusion with cholecystokinin-8 (100 M but not 1 M or 10 nM) increased the dialysate levels of dopamine without affecting those of DOPAC or HVA. At low concentrations (1 M and 10 nM but not 1 nM), cholecystokinin-8 counteracted the inhibitory effect of apomorphine (0.05 mg/kg, s. c.) on dopamine release. This counteraction was antagonized by perfusion with the cholecystokinin-8 antagonist proglumide (3 M). At this concentration, proglumide perfused alone was without effect on basal or apomorphine-reduced levels of dopamine. The results indicate a facilitatory effect of cholecystokinin-8 on dopamine release in rat neostriatum only at high concentrations. At lower concentrations, cholecystokinin-8 appears to modulate dopamine release by an inhibitory effect on dopamine autoreceptors possibly involving an intramembrane interaction between presynaptic cholecystokinin-8 receptors and dopamine autoreceptors.
IMPRINTING IN PLANTS AFFECTS THE ENDOSPERM BUT NOT THE EMBRYO: Genomic imprinting, though most extensively studied in mammals, has long been known to perform an important role in seed development in flowering plants. In this chapter, an overview of what is known to date about genomic imprinting in flowering plants and how this knowledge came into being will be given.
There are more than 70 known unisexual species of fishes, amphibians, and reptiles. They are all-female populations of interspecific hybrid origin that reproduce without sex via altered gametogenetic mechanisms. They are either sperm independent as in parthenogenesis or sperm dependent as in gynogenesis or hybridogenesis, which causes clonal (or hemiclonal) inheritance. The first two modes of reproduction produce species composed of genetically isolated clones. In many previous papers, origin and ancestry, clonal diversity based on allozyme or mitochondrial DNA variation, ecology and evolution of unisexual vertebrates were discussed. This chapter reviews the role of mutations in genome diversity of some unisexual vertebrates revealed by DNA fingerprinting and/or by locus-specific PCR. It also describes recent data on molecular structure of unstable microsatellite loci and their allelic variants in parthenogenetic lizard species. The available data demonstrate that microsatellite mutations as well as point mutations in flanking regions make significant contribution in genome diversity of, at least some, clonaly reproduced vertebrates.
The oral absorption of two known active principles of Hypericum perforatum, namely hyperforin and hypericin, was studied in an open, single dose, two-way, randomized, cross-over study involving 12 healthy subjects (six males and six females). Alcoholic Hypericum extract (300 mg, containing 5% hyperforin and 0.3 % hypericin) was administered in the morning after 12 hours fasting. The formulation was administered as softgel capsules containing, inter alia, soya oil together with the herbal extract. A second standard formulation in two piece hard gelatin capsules was also used for comparison purposes. Blood was sampled from the subjects at different times after drug administration and the plasma was analysed according to published analytical methods for the determination of hyperforin and hypericin. Peaks of plasma concentration, Cmax of hyperforin were 168.35 ng/ml +/- 57.79 for the soft gelatin formulation (CV=34.32, n=12) and 84.25 ng/ml +/- 33.51 for the hard gelatin capsule (CV=39.77, n=12). The Tmax values for hyperforin were 2.50 h +/- 0.83 for the soft gelatin formulation compared to 3.08 h +/- 0.79 for the reference formulation, whereas the total AUC were respectively 1482.7 h x ng/ml +/- 897.13 and 583.65 h x ng/ml +/- 240.29. As for hypericin, plasma levels were detectable in approximately half of the subjects treated. However also in this case the soft gelatin capsules exhibited a higher individual absorption when compared with the corresponding data for the hard gelatin capsules.
Vietnamese geckos of the genus Hemidactylus, previously considered to belong to the triploid all-female species H. garnotii Dumeril and Bibron (n = 23; 3n = 70), prove instead to belong to the new triploid all-female species H. vietnamensis (n = 20; 3n = 60). It is suggested that H. karenorum Theobald from Vietnam and Burma, seemingly closely related to H. vietnamensis, is also an all-female species. The new species is markedly different in morphology. Neither karyological nor electrophoretic analyses support the origin of H. vietnamensis by hybridization among the sympatric bisexual species H. bowringii Dumeril and Bibron, H. frenatus Dumeril and Bibron and Cosymbotus platyurus (Schneider). H. frenatus from Vietnam has a diploid number of 2n = 40. The number obtained is the same as the 2n number of H. frenatus from Australia, but distinct from the number in this species from Taiwan (2n = 46).
Restriction enzymes were used to assay variation among mitochondrial DNAs from parthenogenetic and sexual species of Lacerta. This permitted identification of the sexual species that acted as the maternal parent of the various hybrid-parthenogenetic lineages. Lacerta mixta was the maternal parent for both L. dahli and L. armeniaca, L. valentini was the maternal parent for L. uzzelli, and L. raddei was the maternal parent of L. rostombekovi. The maternal ancestry of L. unisexualis is not as clear. The sample of L. nairensis was very similar to one from a population of L. raddei and either species could be the maternal parent of L. unisexualis. The parthenogenetic species all had very low nucleotide diversity in absolute terms and in comparison to their sexual relatives. The close similarity between mtDNAs from the parthenogenetic species and their respective sexual maternal ancestor species provides strong evidence for the recent origin of the parthenogens. The low diversity of the parthenogens indicates that few females were involved in their origins; the maternal parents of L. dahli and L. armeniaca could have come from a single population. The patterns of mtDNA variation in Lacerta are very similar to those in Cnemidophorus and Heteronotia, establishing recent and geographically restricted origins as a general feature of parthenogenetic lizards.
Contrary to other unisexual vertebrates except a little-known fossorial snake, the Indo-Pacific anthropophilous, parthenogenetic lacertilian Lipododactylus lugubris is vastly more widespread than its bisexual relatives. At the same time, it shows negligible enzyme polymorphism and low overall heterozygosity in its usual diploid condition, which suggests the possibility that hybridization did not intervene when thelytoky was brought about. Clones are in much higher proportion among the sympatric triploids, but they too have a low relative heterozygosity, compounded by gene dosage restriction since no more than two out of the three alleles have been found expressed at any locus. Isozyme data suggest an origin of the complex in South East Asia, which conclusion is substantiated by the presence of a bisexual sibling species in the Philippine Islands.
The genetic diversity of 34 loci was surveyed from among five populations of the supposed conspecific taxa Lacerta c. caucasica, L. c. alpina, and L. c. daghestanica. Twelve loci exhibited variation. Fixed or nearly fixed allelic differences between L. c. caucasica and L. c. daghestanica were found at two loci, mannose-6-phosphate isomerase-A and creatine kinase-C. These two taxa differed from L. c. alpina at eight loci. Nei’s (1978) genetic distance values among populations of L. c. daghestanica ranged from 0.000 – 0.029, between L. c. caucasica and L. c. daghestanica from 0.076 – 0.087 and between L. c. alpina and the other taxa from 0.472 – 0.501. Fixed allelic differences and consistent morphological character states support the recognition of these three taxa as separate species. Therefore, we recommend use of the names L. alpina, L. caucasica, and L. daghestanica for these taxa.
Five proteins (mannosephosphate isomerase, glucosephosphate isomerase, lactate dehydrogenase, creatine kinase, hemoglobin) were examined for six bisexual Transcaucasian taxa related to Lacerta saxicola (Lacerta valentini, L. portschinskii, L. raddei raddei, L. r. nairensis, L. mixta, L. parvula) and four unisexual taxa (Lacerta armeniaca, L. dahli, L. rostombekovi, L. unisexualis). Heterozygosity in the bisexual taxa was very limited for this sample of proteins. All individuals examined of each unisexual were heterozygous at loci specifying at least two of these proteins (L. armeniaca: mannosephosphate isomerase and creatine kinase; L. dahli, mannosephosphate isomerase and hemoglobin; L. rostombekovi, glucosephosphate isomerase, mannosephosphate isomerase and hemoglobin; L. unisexualis, glucosephosphate isomerase, mannosephosphate isomerase and creatine kinase). High levels of heterozygosity in unisexuals appears to result from the hybrid origin of the unisexuals. The exact combinations of alleles present in unisexuals would readily result from certain crosses among the bisexuals, and from no others. The first point supports the hypothesis that hybridization accounts for the observed heterozygosity, the second identifies, biochemically at least, the probable parents. On these biochemical grounds, L. armeniaca arose by hybridization of L. valentini and L. mixta; L. unisexualis from L. valentini and L. r. nairensis; L. rostombekovi from L. r. raddei and L. portschinskii; and L. dahli from L. portschinskii and L. mixta. With regard to altitudinal distribution, vegetational associations and geographic distribution, each unisexual species appears to be intermediate between its putative parental species. L. armeniaca, L. unisexualis and L. rostombekovi all live in drier situations than either parental species. L. dahli is an exception since it occupies slightly more moist habitats than L. portschinskii. Biogeographical considerations appear to place the age of L. unisexualis and L. rostombekovi at greater than 5000 years. It is possible that their occupancy of more extreme habitats than their parental species represents a relic ecology, reflecting the adaptations of the parental bisexual species when the unisexual species arose, rather than a weed habitat into which they moved to escape from competition with their parental species. The fixed heterozygosity of the unisexual species of Lacerta indicates that the restitution of somatic diploidy results either from a premeiotic endoduplication without cytokinesis, or from fusion of the female pronucleus with one of the second division meiotic products of the first polar nucleus. The first mechanism is inconsistent with the number of bivalents reported, the second is otherwise unknown in organisms in which the first polar nucleus becomes a polar body. The bisexual taxa are treated as several distinct species, four pairs of which are partly sympatric with little or no hybridization. Morphological and ecological differences between the other taxa are so great that there seems little question about specific distinctness. The degree of biochemical and morphological difference between these non-sympatric taxa is as great as that between those that do occur sympatrically without fusing. The formation of parthenogenetic species as a result of past hybridization between some pairs indicates a great selective disadvantage to these pairs of hybridizing, and is thus compelling evidence that the two members of each pair are not conspecific.
The phenotypic consequences of parthenogenesis in the hybrid clonal complex of lizards, Cnemidophorus tesselatus are examined, as they relate to (1) the concordance of morphological variation with electrophoretically-detected clonal heterogeneity and (2) the relative amounts of phenotypic variations in populations of tesselatus differing in clonal structure and in populations of an ancestral sexual species, C. tigris. Sympatric clones of tesselatus generated by multiple hybridization between the same two sexual species are heterogeneous in four of thirteen morphological characters, as are sympatric diploid and triploid clones. Morphological variability in six of nine meristic body scale characters reflects the different amounts of genetic variation in uniclonal and multiclonal populations of tesselatus and in populations of the sexual tigris. However, sexual and parthenogenetic populations are similar in variability of four size- or growth-related morphological characters. Environmental effects on the continuously developing size-correlated characters may obscure any genotypic component to variation in these characters, while the scale characters, subject to environmental influence during the shorter period of embryonic development, may have larger genotypic components. Also, parthenogenetic and sexual genotypes may differ in their developmental responses to environmental change, as the surviving genotypes of a parthenogenetic clonal complex may be more phenotypically plastic than sexual genotypes for ecologically important physiological and morphological traits, such as growth and size.
Most parthenogenetic animal taxa which have been investigated electrophoretically, cytologically, or with tissue grafting techniques are clonally diverse. I have examined data on multiclonal parthenogenetic populations using ecological diversity measures to elucidate patterns of clonal coexistence. Analysis of a discrete population cage experiment on clones of Drosophila mercatorum revealed monotonic decay of clonal diversity and evenness; however, in a continuous generation cage, clonal diversity appeared to stabilize. Clonal diversity and evenness fluctuated widely over time in several multiclonal populations of Daphnia magna although no clonal extinction was observed. There were few spatial trends in clonal diversity and evenness within parthenogenetic taxa. It is suggested that the degree of clonal differentiation, determined by the mode of clonal origin, is important in determining whether or not selection occurs among sympatric clones
Lacertca raddei and Lacerta nairensis have been recognized as two separate species based on morphology and behavior, and each has been implicated as a sexual parent of different parthenogenetic forms. However, recent mitochondrial DNA work failed to distinguish these two as separate species. We examined genetic diversity at 36 allozyme loci from six populations of L. nairensis and four populations of L. raddei. There were no fixed allelic differences between the two. Mean heterozygosity was slightly higher among populations of L. raddei than among populations of L. nairensis. A Distance Wagner phenogram showed that the northernmost population of L. raddei clustered with the L. nairensis populations; the other L. raddei populations clustered together. We suggest that L. raddei and L. nairensis may not be separate species, a finding which has important implications for determining the origins of some parthenogenetic Lacerta.
Genetic diversity at 37 allozyme loci was surveyed from Lacerta valentini (4 populations), L. portschinskii and L. rudis (1 population each). The number of polymorphic loci ranged from 1 (L. valentini) to 11 (L. rudis). Mean heterozygosity (direct count) ranged from 0.003 (L. valentini) to 0.071 (L. rudis). Nei's (1978) genetic distance ranged from 0-0.03 among populations of L. valentini, 0.127-0.163 between L. valentini and L. rudis and 0.366-0.487 between L. portschinskii and the two other taxa. Indices of genetic variability for species having disjunct distributions were lower than in species with contiguous distributions, similar to the case of insular populations, which have lower values than do mainland populations.
Genetic diversity at 35 allozyme loci was surveyed in seven populations of Lacerta armeniaca. Fixed heterozygotes were present at 16 loci, with homozygotes at 17 loci. Variation occurred at two loci, one in each of two populations, indicating one widespread clone, one restricted clone, and one apparently restricted clone. The low level of variation in this species suggests a recent restricted origin, involving few parental individuals.
Hybrid triploid males in sympatric populations of some parthenogenetic and bisexual species of rock lizards of the genus Lacerta
- I S Darevsky
- T Uzzell
- L A Kupriyanova
- F D Danielyan
Darevsky, I. S., Uzzell, T., Kupriyanova, L. A. and Danielyan, F. D. (1972) Hybrid triploid males in sympatric populations of some parthenogenetic and bisexual species of rock lizards of the genus Lacerta. Bull. Mos-kovskogo Obshch. Ispyt. Prir. Odtel. Biol. 78, 48-58.
Rock Lizards of the Caucasus: systematics, ecology and phylogenesis of the poly-morphic groups of Caucasian rock lizards of the subgenus Archaeolacerta
- I S Darevsky
Darevsky, I. S. (1967) Rock Lizards of the Caucasus: systematics, ecology and phylogenesis of the poly-morphic groups of Caucasian rock lizards of the subgenus Archaeolacerta. Nauka, Leningrad (English translation).
Intraclonal mating in the par-thenogentic lizard species Lacerta unisexualis
- I S Darevsky
- F D Danielyan
- T M Sokolova
- Yu M Rozonov
Darevsky, I. S., Danielyan, F. D., Sokolova, T. M. and Rozonov, Yu. M. (1989) Intraclonal mating in the par-thenogentic lizard species Lacerta unisexualis. In Evolution and ecology of unisexual vertebrates (Dawley, R. M. and Bogart, J. P., eds), pp. 228-235. Bull. N. Y. State Mus. ~-466.
Clonal diversity in Cnemidophorus: ecological and morphological consequences. In Evolution and ecology of unisexual vertebrates
- E D Parker
- J M Walker
- M A Paulissen
Parker, E. D., Walker, J. M., and Paulissen, M. A. (1989) Clonal diversity in Cnemidophorus: ecological and morphological consequences. In Evolution and ecology of unisexual vertebrates. (Dawley, R. M. and Bogart, J. P., eds), pp. 72-86. Bull. N. Y. State Mus. ~f466. Pasteur, G., Agn6se, J.-F., Blanc, Ch. P. and Pasteur, N. (1987) Polyclony and low relative heterozygosity in a widespread unisexual vertebrate. Lepidodactylus lugubris (Sauria). Genetica 75, 71-79.
Hybrid triploid males in sympatric populations of some parthenogenetic and bisexual species of rock lizards of the genus Lacerta
- Darevsky
Genetic variation among populations of the Caucasian rock lizard Lacerta raddei complex from Armenia
- Bobyn
Molecular phylogeny of the sexual species of Caucasian rock lizards, genus Lacerta, subgenus Archaeolacerta
- R W Murphy
- I S Darevsky
- R D Macculloch
- J Fu
- F Danielyan