
Genetic structure and historical demography of Schizothorax nukiangensis (Cyprinidae) in continuous habitat
Author(s) -
Chen Weitao,
Du Kang,
He Shunping
Publication year - 2015
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.1413
Subject(s) - biological dispersal , biology , population , genetic structure , ecology , isolation by distance , philopatry , gene flow , phylogeography , zoology , genetic variation , phylogenetics , genetics , gene , demography , sociology
Geographic distance, different living habitats or Pleistocene climatic oscillations have frequently been found to shape population genetic structure in many species. The genetic structure of Schizothorax nukiangensis , a high altitude, valuable fish species, which is distributed throughout the Nujiang River, was investigated by mitochondrial DNA sequence analysis. The cytochrome c oxidase subunit I ( COI ), cytochrome b ( cytb ), and the mitochondrial control region ( MCR ) of S. nukiangensis were concatenated for examination of population structure and demographic history. The concatenated data set (2405 bp) implied a pronounced genetic population structure (overall F ST = 0.149) and defined two population units. Strong differentiation was detected between the Sanjiangkou ( SJK ) population and other populations due to environmental heterogeneity, dispersal ability, and/or glacial cycles. Additional DNA sequencing of the nuclear RAG 2 gene also examined significant differentiation between two units and between SJK and the upstream populations (U‐unit). Recent expansion events suggest that S. nukiangensis may have undergone a rapid increase during warm interglacial periods. Surprisingly, S. nukiangensis appears to have undergone an obvious expansion during the last glaciations ( LG ) for cold hardiness and a sharp contraction from 1.5 ka to the present. However, two population units exhibited different reflections during the LG , which might be closely related to their living habitats and cold hardiness. A clear pattern of isolation by distance was detected in S. nukiangensis due to feeding habits, limited dispersal ability, and/or philopatry. It is vitally important that more attention be given to S. nukiangensis due to low genetic diversity, lack of gene flow, and recent population contraction.