Genetic diversity and taxonomic status of Gymnocypris chilianensis based on the mitochondrial DNA cytochrome b gene

Abstract

ABSTRACT. In order to study the genetic diversity and taxonomic status of Gymnocypris chilianensis on a molecular level, the mitochondrial DNA cytochrome b gene was sequenced for 74 individuals of G. chilianensis from two locations (Heihe River and Shule River) and 42 individuals of its affinis species Gymnocypris przewalskii. Analyses of genetic diversity and sequence differences were conducted for these samples, combined with the analysis of 30 homologous sequences of another affinis species Gymnocypris eckloni, which were downloaded from GenBank. The results showed that both the haplotype diversity (h = 0.9820) and nucleotide diversity (π = 0.0039) of the Shule River G. chilianensis were lower than the other populations, thus, the Shule River G. chilianensis should be prioritized for protection because of its lower genetic diversity level. The results of sequence analysis showed that the genetic distance between the Heihe River G. chilianensis population and the Shule River G. chilianensis population was 0.0064, and the 9253-9260 (2015) genetic distance between these two populations and the G. przewalskii population was 0.0838 and 0.0810, respectively. The genetic distance between the two G. chilianensis populations and the G. eckloni population was 0.0805 and 0.0778, respectively. Analysis of sequence differences indicates that G. chilianensis is sufficiently diverged from G. przewalskii and G. eckloni to the extent that it has reached species level, thus, G. chilianensis can be considered an independent species of Gymnocypris.

The complete mitochondrial DNA of Gymnocypris potanini Herzensten and comparative mitogenomic analyses in Gymnocypris species

“…According to the results based on the mitochondrial DNA cytochrome b gene or mitogenoma sequences, G. przewalskii and G. eckloni were monophyletic in the trees. Furthermore, G.dobula and G. namensis also had a close genetic relationship, which were consistent with the findings of previous molecular analyses (Qi et al 2013;Zhang et al 2015). Thus, the mitochondrial genome data and phylogenetic analysis of the G. potanini Herzensten can enrich the evolutionary research of Gymnocypris.…”

The complete mitochondrial DNA of Gymnocypris potanini firmispinatus and comparative mitogenomic analyses of the Gymnocypris species

“…All Gymnocypris species had close relationship, G. przewalskii, G. przewalskii ganzihonensis, and G. eckloni were monophyletic in the trees, which were consistent based on the mitochondrial DNA cytochrome b gene or mitogenoma sequences. In agreement with the findings of previous molecular analyses (Qi et al 2013;Zhang et al 2015), G. dobula and G. namensis also had a close genetic relationship, however, which had a closer distance with G. eckloni chilianensis as the subspecies of G. eckloni (Zhang et al 2015). Thus, the mitochondrial genome data and phylogenetic analysis of the G. potanini firmispinatus can enrich the evolution research of Gymnocypris.…”

Phylogeny and genetic diversity reveal the influence of Qinghai-Tibet Plateau uplift on the divergence and distribution of Gymnocypris species

“…The Qinghai-Tibet Plateau (QTP), known as the roof of the world and the Chinese water tower, is rich in biological resources and river systems (Favre et al 2015;Zhao et al 2009). Due to the uniqueness of the geographical environment of the QTP, strong adaptation is required for species to live there (Meyer et al 2017;Yang et al 2014;Zhang et al 2015a). In the past few million years, with uplift of the QTP, biological diversity has undergone major changes, especially due to adaptive evolution (Favre et al 2015;Wang et al 2017;Zhang et al 2017).…”

“…Uplift of the QTP began in the Pliocene and continued until the Quaternary glaciations (Favre et al 2015;Meyer et al 2017). The QTP is the highest-altitude and youngest plateau worldwide and has typical geographical environmental characteristics such as a high altitude, low oxygen, strong ultraviolet radiation and low temperatures in winter (Zhang et al 2015a;Guan et al 2014;Wu et al 1992). At the end of the Pliocene, 0.2-2.0 million years ago (Mya), due to neotectonic movement, the surrounding mountain ridges formed Qinghai Lake (Bian et al 2000;Yuan et al 1990).…”

“…Gymnocypris species is an indigenous fish unique to the QTP and is an ideal model for studying the relationship between plateau uplift and biological evolution. For millions of years, Gymnocypris species has evolved in response to the environmental and geographical changes of the plateau (Zhang et al 2013(Zhang et al , 2015aTong et al 2016;Kai et al 2005;Zhao et al 2007). Maternal inheritance, a lack of recombination and a rapid evolutionary rate are the main features of mitochondrial DNA (mtDNA), which is widely used as a molecular evolutionary tool to examine species origins and evolutionary mechanisms (O'Bryan et al 2010;Su et al 2014;Zhang et al 2015b).…”