title: Genetic structure and demographic history of the endangered and endemic schizothoracine fish Gymnodiptychus pachycheilus in Qinghai-Tibetan Plateau.
abstract: The endangered schizothoracine fish Gymnodiptychus pachycheilus is endemic to the Qinghai-Tibetan Plateau (QTP), but very little genetic information is available for this species. Here, we accessed the current genetic divergence of G. pachycheilus population to evaluate their distributions modulated by contemporary and historical processes. Population structure and demographic history were assessed by analyzing 1811-base pairs of mitochondrial DNA from 61 individuals across a large proportion of its geographic range. Our results revealed low nucleotide diversity, suggesting severe historical bottleneck events. Analyses of molecular variance and the conventional population statistic FST (0.0435, P = 0.0215) confirmed weak genetic structure. The monophyly of G. pachycheilus was statistically well-supported, while two divergent evolutionary clusters were identified by phylogenetic analyses, suggesting a microgeographic population structure. The consistent scenario of recent population expansion of two clusters was identified based on several complementary analyses of demographic history (0.096 Ma and 0.15 Ma). This genetic divergence and evolutionary process are likely to have resulted from a series of drainage arrangements triggered by the historical tectonic events of the region. The results obtained here provide the first insights into the evolutionary history and genetic status of this little-known fish.
authors.affiliation: 1 College of Grassland Science, Key Laboratory of Grassland Ecosystem (Ministry of Education), Pratacultural Engineering Laboratory of Gansu Province, Sino-U. S. Centers for Grazing land Ecosystem Sustainability, Gansu Agricultural University, Lanzhou 730070, P. R. China.
authors.forename: Junhu
authors.initials: J
authors.lastname: Su
authors.forename: Weihong
authors.initials: W
authors.lastname: Ji
authors.forename: Yanming
authors.initials: Y
authors.lastname: Wei
authors.forename: Yanping
authors.initials: Y
authors.lastname: Zhang
authors.forename: Dianne M
authors.initials: DM
authors.lastname: Gleeson
authors.forename: Zhongyu
authors.initials: Z
authors.lastname: Lou
authors.forename: Jing
authors.initials: J
authors.lastname: Ren
mesh_terms: D000818:Animals; D002681:China; D003247:Conservation of Natural Resources; D003530:Cyprinidae / Q000235:genetics* / Q000502:physiology*; D003710:Demography; D056727:Endangered Species; D010802:Phylogeny
keywords: Gymnodiptychus pachycheilus; Qinghai-Tibetan Plateau; demographic history; genetic structure; schizothoracine fishes