Publications (6)24.33 Total impact
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Article: Complete mitochondrial genomes resolve phylogenetic relationships within Bombina (Anura: Bombinatoridae).
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ABSTRACT: A highly resolved and time-calibrated phylogeny based on nucleotide variation in 18 complete mitochondrial genomes is presented for all extant species and major lineages of fire-bellied toads of the genus Bombina (Bombinatoridae). Two sets of divergence time estimates are inferred by applying alternative fossil constraints as minima. Divergence time estimates from both analyses differed for the two oldest nodes. The earliest phylogenetic split occurred between small- and large-bodied Bombina (subgenera Bombina and Grobina, respectively) either in the Middle Oligocene or the Early Miocene. East Asian B. orientalis and European B. bombina + B. variegata diverged in the early or Middle Miocene. Divergence times inferred using the alternative fossil calibration strategies converged for the younger nodes, with broadly overlapping HPD intervals. The split between Bombina bombina and B. variegata occurred in the Late Miocene of Europe and somewhat preceded another deep mtDNA division between the Balkan B. v. scabra and B. v. variegata inhabiting the Carpathian Mts. Concurrently, the genetically distinct B. maxima diverged from other Grobina in southeast Asia in the Late Miocene or Pliocene. Our mtDNA phylogeny and a new species-tree analysis of published data (nuclear and mtDNA) suggest that B. fortinuptialis, B. lichuanensis and B. microdeladigitora may be conspecific geographic forms that separated due to Pleistocene climatic fluctuations in southeastern Asia. In the western Palearctic, the Late Pliocene to Pleistocene climatic vagaries most probably induced vicariant events in the evolutionary history of B. variegata that led to the formation of the two Balkan B. v. scabra lineages and the allopatric B. v. pachypus in the Apennine Peninsula. Divergence among B. bombina mtDNA lineages is low, with an Anatolian Turkey lineage as the sister group to the European mtDNA clades. In sum, Miocene diversification in the genus Bombina established six allopatrically distributed major mtDNA lineages that diversified during the Pliocene and Pleistocene and have survived until the present. The narrow habitat requirements of fire-bellied toads and extensive environmental changes throughout the Palearctic in the Neogene may have contributed to a putatively high extinction rate in these anurans resulting in the current east/west disjunction of their ranges.Molecular Phylogenetics and Evolution 05/2013; · 3.61 Impact Factor -
Article: Mitochondrial genome organization and divergence in hybridizing central European waterfrogs of the Pelophylax esculentus complex (Anura, Ranidae).
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ABSTRACT: Natural transfer of mitochondrial DNA has occurred between three western Palaearctic waterfrog taxa: Pelophylax lessonae, Pelophylax ridibundus and their hybridogenetic hybrid, Pelophylax kl. esculentus. The transfer is asymmetric with most P. kl. esculentus and approximately one third of all central European P. ridibundus having mtDNA derived from P. lessonae (L-mtDNA). We obtained complete nucleotide sequences of multiple mitochondrial genomes (15,376-78 bp without control regions) from all 3 taxa, including a P. ridibundus frog with introgressed L-mtDNA. The gene content and organization of the mitogenomes correspond to those typical of neobatrachians. Divergence between the mtDNAs of P. lessonae and P. ridibundus is high with an uncorrected p-distance of 11.9% across the entire mitogenome. However, the rate of nucleotide substitution depends on the degree of functional constraint with up to 30-fold differences in levels of divergence. In general, mitochondrial genes encoding the translational machinery evolve very slowly, whereas genes encoding polypeptides of the electron transport system, especially the ND genes, evolve rapidly. Only 25 of 211-213 observed amino acid replacements could be classified as radical and are therefore more likely to be exposed to selection. A disproportionately high number of amino acid substitutions has occurred in the ND4, ND4L and cytb genes of the P. lessonae lineage (including 36% of all radical changes). In contrast to the interspecific divergence, nucleotide polymorphism within L- and R-mtDNA is very low: L-mtDNA haplotypes differed on average by only 19 nucleotides, while there was no variation within two mtDNAs derived from P. ridibundus. This is an expected finding considering that we have sampled a post-glacial expansion area. Moreover, the introgressed L-mtDNA on a P. ridibundus background differed from other L-mtDNAs by only a few substitutions, indicative of a very recent introgression event. We discuss our findings in the context of natural selection acting on L-mtDNA and its potential significance in cytonuclear epistasis.Gene 09/2011; 491(1):71-80. · 2.34 Impact Factor -
Article: Nuclear and mitochondrial phylogeography of the European fire-bellied toads Bombina bombina and Bombina variegata supports their independent histories.
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ABSTRACT: Exact location and number of glacial refugia still remain unclear for many European cold-blooded terrestrial vertebrates. We performed a fine-scaled multilocus phylogeographic analysis of two Bombina species combining mitochondrial variation of 950 toads from 385 sites and nuclear genes (Rag-1, Ncx-1) from a subset of samples to reconstruct their colonization and contemporary variation patterns. We identified the lowlands northwest of the Black Sea and the Carpathians to be important refugial areas for B. bombina and B. variegata, respectively. This result emphasizes the importance of Central European refugia for ectothermic terrestrial species, far north of the Mediterranean areas regarded as exclusive glacial refugia for the animals. Additional refugia for B. variegata have been located in the southern Apennines and Balkans. In contrast, no evidence for the importance of other east European plains as refugial regions has been found. The distribution of mtDNA and Ncx-1 variation suggests the presence of local refugia near the Black Sea for B. bombina; however, coalescent simulations did not allow to distinguish whether one or two refugia were present in the region. Strong genetic drift apparently accompanied postglacial expansions reducing diversity in the colonization areas. Extended sampling, coupled with the multilocus isolation with migration analysis, revealed a limited and geographically restricted gene flow from the Balkan to Carpathian populations of B. variegata. However, despite proximity of inferred B. bombina and B. variegata refugia, gene exchange between them was not detected.Molecular Ecology 08/2011; 20(16):3381-98. · 5.52 Impact Factor -
Article: Phylogeography of the fire-bellied toads Bombina: independent Pleistocene histories inferred from mitochondrial genomes.
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ABSTRACT: The fire-bellied toads Bombina bombina and Bombina variegata, interbreed in a long, narrow zone maintained by a balance between selection and dispersal. Hybridization takes place between local, genetically differentiated groups. To quantify divergence between these groups and reconstruct their history and demography, we analysed nucleotide variation at the mitochondrial cytochrome b gene (1096 bp) in 364 individuals from 156 sites representing the entire range of both species. Three distinct clades with high sequence divergence (K2P = 8-11%) were distinguished. One clade grouped B. bombina haplotypes; the two other clades grouped B. variegata haplotypes. One B. variegata clade included only Carpathian individuals; the other represented B. variegata from the southwestern parts of its distribution: Southern and Western Europe (Balkano-Western lineage), Apennines, and the Rhodope Mountains. Differentiation between the Carpathian and Balkano-Western lineages, K2P approximately 8%, approached interspecific divergence. Deep divergence among European Bombina lineages suggests their preglacial origin, and implies long and largely independent evolutionary histories of the species. Multiple glacial refugia were identified in the lowlands adjoining the Black Sea, in the Carpathians, in the Balkans, and in the Apennines. The results of the nested clade and demographic analyses suggest drastic reductions of population sizes during the last glacial period, and significant demographic growth related to postglacial colonization. Inferred history, supported by fossil evidence, demonstrates that Bombina ranges underwent repeated contractions and expansions. Geographical concordance between morphology, allozymes, and mtDNA shows that previous episodes of interspecific hybridization have left no detectable mtDNA introgression. Either the admixed populations went extinct, or selection against hybrids hindered mtDNA gene flow in ancient hybrid zones.Molecular Ecology 07/2007; 16(11):2301-16. · 5.52 Impact Factor -
Article: Limited mitochondrial DNA introgression in a Bombina hybrid zone
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ABSTRACT: We analysed the variation at mitochondrial DNA (mtDNA) and six allozyme loci in two transects across a hybrid zone between the fire-bellied toads Bombina bombina and Bombina variegata in southern Poland. The mtDNA cline was narrower than allozyme clines in one transect (Przemyśl, β = 0.435, w = 3.42 km) and shifted to the B. bombina side in both (near Kraków by 1.32 km, α = 0.437, and near Przemyśl by 0.97 km, α = 0.319). Cytonuclear associations were weak. Narrowed mtDNA clines could be a by-product of female demography and lowered effective population size of mtDNA. Alternatively, restricted mtDNA introgression is a likely result of negative epistasis in recombinants augmented by environment-dependent selection because divergence of Bombina mitochondrial and nuclear genomes is large. The shift of the mtDNA cline, contrary to expectations from initial mating preferences and fecundity differences between the species, suggests that on the B. bombina side of the zone hybrid females with B. variegata mtDNA have a higher chance of leaving progeny. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 91, 295–306.Biological Journal of the Linnean Society 05/2007; 91(2):295 - 306. · 2.19 Impact Factor -
Article: Hybridization of Bombina bombina and B. variegata (Anura, Discoglossidae) at a sharp ecotone in western Ukraine: comparisons across transects and over time.
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ABSTRACT: Bombina bombina and B. variegata are two anciently diverged toad taxa that have adapted to different breeding habitats yet hybridize freely in zones of overlap where their parapatric distributions meet. Here, we report on a joint genetic and ecological analysis of a hybrid zone in the vicinity of Stryi in western Ukraine. We used five unlinked allozyme loci, two nuclear single nucleotide polymorphisms and a mitochondrial DNA haplotype as genetic markers. Parallel allele frequency clines with a sharp central step occur across a sharp ecotone, where transitions in aquatic habitat, elevation, and terrestrial vegetation coincide. The width of the hybrid zone, estimated as the inverse of the maximum gradient in allele frequency, is 2.3 km. This is the smallest of four estimates derived from different clinal transects across Europe. We argue that the narrow cline near Stryi is mainly due to a combination of habitat distribution and habitat preference. Adult toads show a preference for either ponds (B. bombina) or puddles (B. variegata), which is known to affect the distribution of genotypes within the hybrid zones. At Stryi, it should cause a reduction of the dispersal rate across the ecotone and thus narrow the cline. A detailed comparison of all five intensively studied Bombina transects lends support to the hypothesis that habitat distribution plus habitat preference can jointly affect the structure of hybrid zones and, ultimately, the resulting barriers to gene flow between differentiated gene pools. This study also represents a resampling of an area that was last studied more than 70 years ago. Our allele-frequency clines largely coincide with those that were described then on the basis of morphological variation. However, we found asymmetrical introgression of B. variegata genes into B. bombina territory along the bank of a river.Evolution 04/2006; 60(3):583-600. · 5.15 Impact Factor
Top Journals
Institutions
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2007–2011
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Jagiellonian University
- Department of Comparative Anatomy
Kraków, Lesser Poland Voivodeship, Poland
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