Gugs Lushai

University of Southampton, Southampton, England, United Kingdom

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Publications (29)66.55 Total impact

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    ABSTRACT: Most organisms represent specialized forms that arose as a result of natural selection and genetic drift to occupy distinct ecological niches. In animals, this process of specialization includes the behaviour of the organisms concerned, honed by locally-induced adaptations to specific host food plants (in herbivores) or prey items (in predators and parasitoids), and possibly reinforced by kairomones, including sex pheromones. The major thrust of evolution is towards ecological specialization as a result of the direct effects of intra- and interspecific competition. Adaptation to new resources lowers such competition and allows survival in new habitats/niches. Other benefits of food resource/habitat switching include ‘enemy free space’. If specialism is the norm for the vast majority of species, what of so-called generalists and generalism, which are widely used terms, but perhaps wrongly so? Does generalism exist or is it a mirage that disappears the closer that it is inspected? We review some of the aspects of specialism and generalism and argue that even apparent generalists are filling distinct ecological niches. Often, generalists are rather specific in terms of food preferences, although they may nevertheless remain opportunistic with an overall broad niche/resource width. When apparent ‘good’ species are examined using molecular (DNA) markers, they are often found to comprise cryptic species. Many generalists may be of this kind. If so, generalism warrants additional investigation to establish its scope and credentials.
    Biological Journal of the Linnean Society 01/2011; · 2.41 Impact Factor
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    ABSTRACT: Anecdotal evidence has long suggested that the African queen butterfly, Danaus chrysippus (L.), is migratory. More recently, records of rapid and seasonal changes in the frequencies of different colour pattern morphs in Tanzania, Ghana, and Kenya have provided further evidence. This paper demonstrates similarly rapid changes in the frequencies of different mitochondrial haplotypes in Nairobi, Kenya over a two-week period. These changes are correlated with changes in the frequencies of homozygous and hybrid colour forms, and are consistent with colour pattern/haplotype associations that have been observed on a continental scale. We conclude that they can only be explained by migration and that mtDNA analysis can be usefully and generally applied in studies of migratory movement.
    Journal of East African Natural History 01/2009;
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    GUGS LUSHAI, HUGH D. LOXDALE fls
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    ABSTRACT: Models of population structure have emphasized the importance of sex in maintaining lineages. This is because, despite the well known ‘two-fold cost of sex’ compared with asex, it is considered that recombination rids the genome of accumulated mutations and increases its potential for adaptive variation. However, asexual lineages of eukaryotic organisms can also rapidly gain genetic variance directly by various mutational processes, thereby proving that so-called ‘clones’ do not have strict genetic fidelity (Lushai & Loxdale, 2002; Loxdale & Lushai, 2003a), whereas the variation so produced may well have adaptive advantage during the evolutionary process. This being so, obligated asexuals or cyclical parthenogens that occasionally indulge in sexual recombination (‘rare sex’) cannot be deemed as ‘evolutionary dead-ends’(Lushai, Loxdale & Allen, 2003a). In addition, the persistence of asexual lineages (i.e. lineage longevity) may also involve the integrity of the telomere region, the physical end of the chromosomes (Loxdale & Lushai, 2003b). In this earlier study on this topic, we argued that the persistence and ultimate senescence of eukaryotic cell lineages (based upon the frequency of ‘capped’ and ‘uncapped’ chromosomes related to telomere functionality; Blackburn, 2000) may directly relate to the survival and persistence of lineages of whole asexual organisms. Aphids are a good model system to test this hypothesis because they show a variety of sexual/asexual reproductive strategies, whereas their mode of asexual reproduction is of the mitotic (= apomictic) type. We also suggested that many aphid lineages require occasional or even rare sexual recombination to re-set telomere length to allow lineages to persist. Ample empirical evidence from diverse taxa, lineages, and different developmental stages now reveals that the telomere states are indeed re-set by recombination (homologous or meiotic), thereby rejuvenating the lineage in question. The generational clock element of telomeric functionality has also been successfully described in artificially-induced mammalian clonal systems. It thus appears that telomere function is a central molecular mechanism instigating and promoting lineage continuity per se. By contrast, we hypothesized that other long-lived asexuals, or the rare category of ancient asexuals such as bdelloid rotifers, have compensatory mechanisms for maintaining chromosome functional integrity, which are somewhat different from conventional telomeric repeats. In the present study, we carry the analogy between eukaryotic cell functionality and aphid lineages a stage further. Here, we hypothesize that the changing frequency of capped and uncapped telomeres, progressing to senescence in a stochastic manner, may be an underlying factor that significantly contributes to population dynamics in asexual lineage evolution. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 90, 719–728.
    Biological Journal of the Linnean Society 03/2007; 90(4):719 - 728. · 2.41 Impact Factor
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    ABSTRACT: Mitochondrial and nuclear DNA information was analysed among four subspecies of the African Queen butterfly, Danaus (Anosia) chrysippus sensu lato (s.l.), along with four other Danaus species drawn from all three subgenera (D. (Danaus) plexippus, D. (Salatura) genutia, D. (A.) gilippus, D. (A.) eresimus) and two outgroup species from the same tribe, Tirumala septentrionis and Amauris niavius. A mitochondrial phylogeny derived from the 12S rRNA (347 bp) and COI (537 bp) loci indicates two very distinct haplotypes for subspecies D. (A.) c. dorippus, dorippus-1 and dorippus-2. Interestingly, dorippus-1, on the one hand, and all other D. (A.) chrysippus haplotypes, on the other, are the most distantly related clades within the genus and have different most recent ancestors from different subgenera, though sharing the common ancestor of the monophyletic genus. A phylogeny based on the EF1- nuclear locus (400 bp) shows that the two well-separated mitochondrial lineages of dorippus are identical for this gene and reciprocally monophyletic to the other D. (A.) chrysippus lineages. Thus, nuclear and cytoplasmic phylogenies are not only discordant, but also suggest that both D. (A.) chrysippus s.l. and subspecies dorippus are polyphyletic. Paradoxically, four African subspecies, chrysippus-orange, chrysippus-brown, alcippus and dorippus, though substantially vicariant, hybridize extensively in East Africa wherever the ranges of two or more of them overlap. Linkage disequilibrium, and hence sexual isolation, in sympatry between colour (nuclear) genes and unlinked mitochondrial (cytoplasmic) loci is consistent across populations and therefore indicates the operation of positive natural selection. Together with data from previous experimental and field work, our results suggest that extensive hybridization occurs among once allopatric or parapatric lineages, that are now nascent species. We deduce that hybridism among lineages in sympatry is currently enforced, in the face of assortative mate choice, by a bacterial symbiont, Spiroplasma, a male-killer that forces females in female-biased populations to pair with heterotypic males. In discussion we emphasize that neither D. (A.) chrysippus s.l. as presently circumscribed, nor its component clades, conform to any established concept of species. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 86, 117–131.
    Biological Journal of the Linnean Society 08/2005; 86(1):117 - 131. · 2.41 Impact Factor
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    ABSTRACT: Classification of the cosmopolitan butterfly genus Danaus (Nymphalidae: Danainae) is revised at subgeneric, specific and subspecific levels, combining for the first time mitochondrial and nuclear DNA sequence information with morphological data. Tree topologies based on the nuclear genome (allozymes, pheromone components, the morphology of all life history stages and nuclear DNA sequences), on the one hand, and mitochondrial DNA, on the other, are incongruent and challenge the current taxonomy of the genus. Although earlier classifications, based on adult morphology alone, are, in general, well supported by an analysis of total evidence, the mitochondrial phylogeny shows that the species D. chrysippus and its subgenus Anosia are deeply paraphyletic. Subspecies dorippus of D. chrysippus is the basal clade of the genus and is reinstated as the species D. dorippus. The former species D. plexaure is demoted to a subspecies of D. eresimus. The specific status of D. erippus, as distinct from D. plexippus, is tentatively supported. On the strength of the new data, division of the monophyletic genus Danaus s.l. into three subgenera Danaus s.s., Salatura and Anosia is unsustainable and is abandoned. Of the 15 terminal clades (taxa) of Danaus s.l. included in the study, 11 are species that broadly conform to the biological species concept. (The West Indian species D. cleophile, missing from our analysis, is the twelfth species). The remaining terminal clades are subspecies of D. chrysippuscomb. nov. and D. dorippusstat. rev. Two sympatric Neotropical species, D. eresimus and D. gilippus, are morphologically distinct and sexually isolated but have nearly identical mitochondrial genomes. In contrast, two partially sympatric Palaeotropical species, D. chrysippus and D. dorippus, are cryptic species that share structural morphology and hybridize but have highly differentiated mitochondrial genomes. D. dorippus is polymorphic for two anciently  diverged  haplotypes  and  its  history  has  possibly  involved  recombinational  speciation  and/or  hybridism. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 144, 191−212.
    Zoological Journal of the Linnean Society 05/2005; 144(2):191 - 212. · 2.66 Impact Factor
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    ABSTRACT: Abstract  The lesser wanderer butterfly, Danaus (Anosia) chrysippus petilia (Stoll) (Lepidoptera: Danainae), has been treated as a subspecies for the last 100 years. New mitochondrial DNA sequence data for D. petilia, in conjunction with allozyme, structural, morphometric and pattern characters, constitute a compelling case for its specific rank. The holotype of D. petilia has never been located and, as the type location is uncertain, a neotype is designated. Fresh material was collected and examined for this project. Danaus petilia and D. chrysippus have been separated at Lydekker's Line for an estimated 1.1 million years, and they remain interfertile. However, as an allopatric taxon, diagnosable from D. chrysippus, D. petilia merits specific status under the phylogenetic species concept. The following pairs of D. chrysippus subspecies are considered to be synonyms, the first member of each pair having priority: chrysippus + aegyptius (subspecies), klugii + infumata (hybrid phenotypes) and orientis +liboria (subspecies).
    Australian Journal of Entomology 01/2005; 44(1):6 - 14. · 0.88 Impact Factor
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    Gugs Lushai, Hugh D Loxdale
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    ABSTRACT: Insects are among the greatest pests of agriculture, horticulture and forestry world-wide, inflicting damage and economic costs both directly and by transmitting plant viruses. Many kinds of insects are now resistant or cross-resistant to pesticides. In order to combat these pests, including for purposes of immediate control or to follow movements in order to better understand pest biology, tracking studies are important. In turn, such studies become useful for modelling and forecasting outbreaks. This is especially so for flying insects, which constitute the greatest threat in terms of the dissemination of plant pathogenic viral diseases. Tracking the aerial displacement of small insects over large spatial scales is difficult mainly because of their size. Dilution effects upon take off, together with displacement by air currents, makes the recapture of individuals tagged e.g. by fluorescent or radio-labelling, highly unlikely and hence estimates of flight direction, speed, duration and distance are hampered, more especially over larger distances. This is generally true also for larger insects. Consequently, molecular markers have been employed in attempts to resolve population structure and dynamics by inference from estimates of gene flow. In this article, we describe some of the methodologies devised that have provided invaluable information relating to the movement of small insect pests, particularly aphids, and explain how these techniques can be added to by detail gained from molecular marker studies. We outline a national survey-system that could be managed by specialist centres and involving members of the Public, that would enable invasive pest insect populations to be tracked efficiently. The logistics of such a survey are discussed along with the benefits. Overall, an insect tracking mandate is described that will promote the standardisation of population movement measurements. Adopting this approach should allow more accurate intra- as well as interspecies comparisons.
    International Journal of Pest Management 01/2004; 50(4):307-315. · 0.72 Impact Factor
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    Hugh D Loxdale, Gugs Lushai
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    ABSTRACT: Artificial cloning and ancient asexuals have impacted upon both scientific and lay thinking in applied and theoretical fields as diverse as medicine and evolution. Hence, this is an opportune time to promote debate and discussion on what maintains a clonal lineage. The genetic fidelity of a clone has been discussed in detail elsewhere [Genet. Res. 79 (2002) 1; Biol. J. Linnean Soc. 79 (2003) 3]. In this paper, we focus on the lineage integrity (=longevity), or physiological lifespan of a clone with respect to senesce in relation to factors controlling telomere functioning. Aspects of cell line research pertinent to eukaryotic clonal lineages are discussed and, in particular, we try to extrapolate aspects of this research and apply it to apomictic (=mitotic) aphid lineages to suggest how they may be maintained. Analogies are made between single cells and individual aphids that senescence through a generation, whilst the respective lineages persist for finite periods, unless that is, compensatory mechanisms have evolved allowing immortality in the one and ancient asexuality in the other. Such comparison may allow fresh insights into the mechanisms of clonal lineage maintenance and evolution. We hypothesise that: (1). the cause of extinction in eukaryotic clonal lineages is due to deleterious effects on key regions of the genome, the chromosomal telomere being one such site; (2). recombination acts as a common mechanism to reset telomere functioning, perhaps more fundamental than its utility to reduce genetic load and maintain adaptability; and (3). ancient lineages persist through time as a function of group-specific compensatory mechanisms that maintain telomere integrity.
    Infection Genetics and Evolution 12/2003; 3(4):259-69. · 2.77 Impact Factor
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    ABSTRACT: Molecular clocks based on sequence change in mitochondrial (mt) DNA have been useful for placing molecular phylogenies in their historical context, thereby enhancing evolutionary insight. Nonetheless, despite their importance to phylogeographers, the methodology is controversial. Here we report on two mitochondrial clocks for the butterfly genus Danaus based on sequences from the cytochrome c oxidase subunit I (COI) and small subunit 12S rRNA (12S) genes. Both clocks are, within the context of Danaus, reliable time-keepers, mutually consistent and, respectively, in agreement with a crustacean COI clock and a molluscan 12S clock. Though we have no fossils with which directly to calibrate sequence divergence rates for Danaus, the 12S molluscan and COI crustacean clocks chosen for comparison were calibrated to radiometrically dated geomorphological events. Our results indicate that the Danaus COI clock evolves approximately four times faster than the 12S clock. Differences between rates of sequence change in terminal sister-taxa are small and likelihood ratio tests do not reject a hypothesis that evolution has been clock-like. The species Danaus chrysippus is paraphyletic and, therefore, invalid. Danaus probably split from its sister-genus Tirumala around 4.9 ± 0.3 million years ago in the early Pliocene. Résumé—Les horloges moléculaires basées sur le changement de séquence de l'ADN mitochondrial (mt) ont été utiles pour replacer les phylogénies moléculaires dans leur contexte historique, et ainsi
    International Journal of Tropical Insect Science 12/2003; 23(04).
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    HUGH D. LOXDALE, GUGS LUSHAI
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    ABSTRACT: It is well established that asexually reproducing viruses and prokaryotes mutate rapidly. In contrast, the eukaryotic clone is often still treated as if it is genetically homogeneous within and between populations, i.e. that it is assumed to show genetic fidelity. However, such fidelity has rarely been tested empirically using the range of high-resolution molecular markers now available, culminating with direct sequencing of the DNA. If such a biological entity as a ‘clone’ really did exist, it would be a fantastic entity, differing from everything else known in biology, i.e. it would possess a population mean but no variance for any particular trait. It would not be amenable to selection and adaptive variation and would thus be unchanging in time and space. In this paper, we argue that the general acceptance of clonal fidelity is a scientific convenience, since the rate of asexual reproduction of eukaryotes is not as fast as that of bacteria and hence it is easier to accept fidelity as a ‘fact’ rather than test for it. We propose that part of the acceptance of fidelity may have a cultural basis and thereby is a kind of ‘pre-Darwinian relic’. Instead, a clonal genotype is perhaps largely a function of marker resolution, i.e. dependent on the number and type of markers employed. If this is so and were enough of the genome explored, perhaps each individual within a clone would be found to differ genetically at particular regions of the chromosomes. The question of what constitutes a clone is not just a semantic one and impacts directly on recent attempts to understand and produce ‘artificial’ clones, especially of mammals. New research is already confirming that mutations and epigenetic influences play a crucial role in the success of cloning attempts. © 2003 The Linnean Society of London. Biological Journal of the Linnean Society, 2003, 79, 3–16.
    Biological Journal of the Linnean Society 05/2003; 79(1):3 - 16. · 2.41 Impact Factor
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    ABSTRACT: Subspecies chrysippus, dorippus and alcippus of the butterfly Danaus chrysippus differ at three biallelic colour gene loci. They have partially vicariant distributions, but their ranges overlap over a substantial part of central and East Africa, where hybridism is commonplace. We now report that the West African subspecies alcippus differs from other subspecies, not only in nuclear genotype but also in mitochondrial haplotype in both allopatry and sympatry. The maintenance of concordant nuclear and cytoplasmic genetic differences in sympatry, and in the face of hybridisation, is prima facie evidence for sexual isolation. Other evidence that suggests alcippus may be isolated from chrysippus and dorippus include differences in sex ratio (SR), heterozygote deficiency at one site and deduced differences in patterns of migration. We suggest that, within the hybrid zone, differential infection of subspecies by a male-killing Spiroplasma bacterium causes SR differences that restrict female choice, triggering rounds of heterotypic mating and consequent heterozygote excess that is largely confined to females. The absence of these phenomena from hybrid populations that test negative for Spiroplasma supports the hypothesis. The incomplete sexual isolation and partial vicariance of alcippus suggests that it is a nascent species.
    Heredity 04/2003; 90(3):236-46. · 4.11 Impact Factor
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    ABSTRACT: Populations of clonal organisms are often represented as being evolutionary inert with persistent genetic fidelity. The advent of molecular methods and the corresponding increased genetic resolution of clonal populations forces a reconsideration of this viewpoint. We review molecular data from viruses, prokaryotes and eukaryotes to support the argument that clones possess a highly dynamic and adaptive genome.
    Biological Journal of the Linnean Society 01/2003; 79:193–208. · 2.41 Impact Factor
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    ABSTRACT: A cross between queen butterflies of the Palaeotropical species Danaus chrysippus and the Neotropical D. gilippus was achieved with difficulty in both directions. Only one progeny (N = 70) was reared comprising sterile males and inviable females in a precisely 1 : 1 ratio. Both prezygotic and postzygotic barriers to gene flow are strong. The result supports Haldane's Rule, to which we propose a minor amendment. The F1 hybrids were intermediate for background colour between the brown (genotype BB) of gilippus and orange (genotype bb) of chrysippus. Most F1 pattern characters were also intermediate. In polymorphic chrysippus populations, because Bb heterozygotes are brown, or nearly so, we suggest the B allele may have evolved towards dominance in sympatry. Hybrid males show positive heterosis for body size. The close similarity of male genitalia between the allopatric, genetically distant species chrysippus and gilippus, compared to their divergence between gilippus and its largely sympatric sister species eresimus, suggest that reinforcement of sexual isolation or reproductive character displacement have evolved in sympatry. © 2002 The Linnean Societyof London, Biological Journal of the Linnean Society, 2002, 76, 535–544.
    Biological Journal of the Linnean Society 07/2002; 76(4):535 - 544. · 2.41 Impact Factor
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    ABSTRACT: Elucidation of the genetic variability of a model insect species, the grain aphid, Sitobion avenae (Fabricius), a predominantly asexual herbivore within the temperate agro-ecosystem tested, was initiated using molecular DNA markers (RAPDs). This revealed genetic profiles that appeared related to host adaptation at the specific level amongst the natural populations colonizing different grasses and cereals (Poaceae) within the same geographic location. These profiles were recorded either as 'specialist' genotypes found on specific grasses, or as 'generalist' genotypes colonizing several host types including cultivated cereals or native grasses. These findings are compared with analogous systems found amongst insect species, including at a higher trophic level, i.e. interactions between hymenopterous aphid parasitoids. As the aphids and their respective plant hosts occur in the same geographical region at the same time, this appears to be a rare example of the evolutionary transition leading to sympatric speciation in insects. Hence, this study highlights the importance of understanding not only the demographic parameters to genetic diversity, but also the more intricate correlation of genetic diversity to host types in agricultural environments.
    Bulletin of Entomological Research 05/2002; 92(2):159-64. · 1.99 Impact Factor
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    Gugs Lushai, Hugh D Loxdale
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    ABSTRACT: Empirical evidence for intraclonal genetic variation is described here for clonal systems using a variety of molecular techniques and implicating a diversity of mechanisms. However, clonal systems are still generally perceived as having strict genetic fidelity. As concepts of genetic variability move from primary sequence data to include epigenetic and structural influences on genetic expression, the ability to detect changes in the genome at short intervals allows precedence to be given to inherent biological variation that is often analytically ignored. Therefore, the advent of powerful molecular techniques, like genome mapping, mean that our concepts of genetic fidelity within eukaryotic clones and the whole philosophy of the 'clone' needs to be re-evaluated and redefined to replace old unproven dogma in this aspect of science.
    Genetics Research 03/2002; 79(1):1-9. · 2.00 Impact Factor
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    Hugh D Loxdale, Gugs Lushai
    Insect movement: mechanisms and consequences, Edited by I.P. Woiwod, D.R. Reynolds, C.D. Thomas, 01/2001: chapter 17: pages 361-386; CABI, Wallingford, U.K.
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    ABSTRACT: The full complement of known greenbug, Schizaphis graminum (Rondani), biotypes found in the USA were subjected to a molecular phylogenetic analysis based on a 1.2-kb portion of the cytochrome oxidase I mitochondrial gene. In addition to these nine biotypes (B, C, E, F, G, H, I, J and K), a probable isolate of the enigmatic biotype A (NY), a 'new biotype' collected from Elymus canadensis (L.) (CWR), and an isolate from Germany (EUR) were included. Schizaphis rotundiventris (Signoret) was included as an outgroup. Genetic distances among S. graminum biotypes ranged from 0.08% to 6.17% difference in nucleotide substitutions. Neighbour-joining, maximum parsimony and maximum likelihood analyses all produced dendrograms revealing three clades within S. graminum. Clade 1 contained the 'agricultural' biotypes commonly found on sorghum and wheat (C, E, K, I, plus J) and there were few substitutions among these biotypes. Clade 2 contained F, G and NY, and Clade 3 contained B, CWR and EUR, all of which are rarely found on crops. The rarest biotype, H, fell outside the above clades and may represent another Schizaphis species. S. graminum biotypes are a mixture of genotypes belonging to three clades and may have diverged as host-adapted races on wild grasses.
    Insect Molecular Biology 05/2000; 9(2):179-84. · 3.04 Impact Factor
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    Journal of Reproduction and Development 03/2000; 46:21-22. · 1.76 Impact Factor
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    ABSTRACT: Tissue from the wing tips of the endangered Apollo butterfly (Parnassius apollo L.) were collected at the end of a breeding season from two sites in Norway: Bandak and Gjendetunga/Bukkelægret about 250 km apart. We investigated the suitability of such non-lethal samples as a source of DNA for studying these populations. Universal mitochondrial DNA (mtDNA) primers were used to amplify DNA from the wing tip extractions. Primers spanning the 12s rRNA region produced 0.35 kb fragments that proved to be invariable in the selected samples when tested for restriction length polymorphisms (RFLPs). These sequences had high homology with analogous mtDNA from other insect sources, e.g. lepidoptera [Spodoptera litura (Fabricius)], and served to authenticate the DNA. Random amplified polymorphic DNA (RAPDs) technology was then used to screen for genetic variability. Of several primers tested, Primer-01 (Operon Kit F) produced a profile that differentiated the population with 88% (P<0.001) efficiency based on multivariate logistic regression analysis of banding profiles. RAPDs were also adapted to develop different molecular marker approaches to screen the samples quickly and cheaply. This work indicates that reliable ‘molecular tags’ can be designed to track demographic populations to study their distribution without endangering the butterfly and highlights the suitability of these markers for use in future population studies.
    Biological Conservation 01/2000; · 3.79 Impact Factor
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    Hugh D. Loxdale, Gugs Lushai
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    ABSTRACT: The majority of insect species do not show an innate behavioural migration, but rather populations expand into favourabl new habitats or contract away from unfavourable ones by random changes of spatial scale. Over the past 50 years, the scientifi fascination with dramatic long–distance and directed mass migratory events has overshadowed the more universal mode of populatio movement, involving much smaller stochastic displacement during the lifetime of the insects concerned. This may be limitin our understanding of insect population dynamics. In the following synthesis, we provide an overview of how herbivorous insec movement is governed by both abiotic and biotic factors, making these animals essentially ‘slaves of their environment’. N displaced insect or insect population can leave a resource patch, migrate and flourish, leaving descendants, unless suitabl habitat and/or resources are reached during movement. This must have constrained insects over geological time, bringing abou species–specific adaptation in behaviour and movements in relation to their environment at a micro– and macrogeographica scale. With insects that undergo long–range spatial displacements, e.g. aphids and locusts, there is presumably a selectio against movement unless overruled by factors, such as density–dependent triggering, which cause certain genotypes within th population to migrate. However, for most insect species, spatial changes of scale and range expansion are much slower an may occur over a much longer time–scale, and are not innate (nor directed). Ecologists may say that all animals and plant are figuratively speaking ‘slaves of their environments’, in the sense that their distribution is defined by their ecolog and genotype. But in the case of insects, a vast number must perish daily, either out at sea or over other hostile habitats having failed to find suitable resources and/or a habitat on which to feed and reproduce. Since many are blown by the vagarie of the wind, their chances of success are serendipitous in the extreme, especially over large distances. Hence, the strategie adopted by mass migratory species (innate pre–programmed flight behaviour, large population sizes and/or fast reproduction) which improve the chances that some of these individuals will succeed. We also emphasize the dearth of knowledge in the variou interactions of insect movement and their environment, and describe how molecular markers (protein and DNA) may be used t examine the details of spatial scale over which movement occurs in relation to insect ecology and genotype.
    Philosophical Transactions of The Royal Society B Biological Sciences 08/1999; 354(1388). · 6.23 Impact Factor

Publication Stats

716 Citations
66.55 Total Impact Points

Institutions

  • 1996–2011
    • University of Southampton
      • • Centre for Biological Sciences
      • • Biological Sciences
      Southampton, England, United Kingdom
  • 2002–2004
    • Agriculture and Agri-Food Canada
      • Eastern Cereal and Oilseed Research Centre (ECORC)
      Ottawa, Ontario, Canada
  • 2003
    • Biotechnology and Biological Sciences Research Council
      Swindon, England, United Kingdom
  • 2000
    • Agricultural Research Service
      Kerrville, Texas, United States
    • Durham University
      • School of Biological and Biomedical Sciences
      Durham, ENG, United Kingdom