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Keywords:

  • mitochondrial DNA;
  • nuclear genes;
  • microsatellite DNA;
  • phylogeography;
  • population genetics;
  • Tibetan Plateau;
  • Phrynocephalus vlangalii

Abstract

Using data from 11 microsatellite DNA loci and a population genetic approach, the phylogeographic patterns of the Qinghai toad-headed lizard Phrynocephalus vlangalii revealed by mitochondrial DNA (mtDNA) were tested and the congruence between the nuclear and mitochondrial genes was examined. Both analysis of molecular variance (AMOVA) and BARRIER analyses suggested that the Arjin and the A'nyemaqen Mountains were significant genetic barriers to contemporary gene flow of the P. vlangalii populations. On the other hand, the Qaidam populations, where no major mountains are present, showed a weak but significant isolation by distance pattern. The patterns of population genetic structure were largely congruent with the phylogeographic patterns inferred from the mtDNA, and therefore, supported the hypothesis that the uplift of the Arjin and the A'nyemaqen Mountains caused the initial vicariant events that led to the formation of the diverged lineages within P. vlangalii. The only major difference between the mtDNA and nuclear DNA (nuDNA) results was the allocation of variance to different hierarchical levels in AMOVA. While the among group component, which were defined by mountains, accounted for most of the mitochondrial variance (81.73%), most of the nuDNA variance was at the among individuals within population level (83.69%). Differences in effective population sizes, social structure and male/female dispersal patterns might have contributed to the discrepancy.