Liu Si-Qing, Tang Qiong-Ying, Li Xiao-Juan, Liu Huan-Zhang
The Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
Dongwuxue Yanjiu. 2013 Oct;34(5):437-45.
Sarcocheilichthys nigripinnis is a small cyprinid fish widely distributed in East Asia, and it has been widely used in biogeographic analyses of freshwater fishes in China. In the present study, 142 S. nigripinnis individuals from 20 sampling sites in eight river systems were collected to investigate its phylogeography and genetic variations.. Populations from the Yellow River represent northern clade and all others represent southern clade. The results showed that 56 haplotypes were identified as mitochondrial DNA (mtDNA) Cyt b gene of 1 140 bp length. Relatively high haplotype diversity (h=0.971) and low nucleotide diversity (π=0.0212) were detected, and the estimated average genetic distance was 2.2%. Moreover, a neighbor-joining(NJ)tree revealed seven strongly supported lineages. Populations from the Yellow River were located at the basal position, whereas the remaining populations were more derived. Our results indicate that S. czerskii might have been evolved from S. nigripinnis in the Yellow River 1.03 Ma. Based on the phylogeographical analysis of S. nigripinnis, we also suggest that vicariance, following mountain uplift and drainage isolation, plays an important role in producing evolutionary lineage differentiations. Moreover, molecular dating estimated that the divergence time of S. czerskii could be dated back to 0.953.92 Ma. Mismatch distribution analysis and neutrality tests also suggested the recent demographic expansions of S. nigripinnis populations, and that the effects of Pleistocene climatic changes could be a vital factor of the population dynamics of S. nigripinnis.
黑鳍鳈是一种小型鲤科鱼类，广泛分布于东亚地区，在中国淡水鱼类的生物地理学分析中得到了广泛应用。在本研究中，采集了来自八个水系20个采样点的142尾黑鳍鳈个体，以研究其系统地理学和遗传变异。黄河流域的种群代表北方分支，其他所有种群代表南方分支。结果显示，在长度为1140 bp的线粒体DNA（mtDNA）细胞色素b基因中鉴定出56个单倍型。检测到相对较高的单倍型多样性（h = 0.971）和较低的核苷酸多样性（π = 0.0212），估计平均遗传距离为2.2%。此外，邻接（NJ）树显示出七个得到强烈支持的谱系。黄河流域的种群位于基部位置，而其余种群则更为进化。我们的结果表明，黑侧条鳈可能在约1.03 Ma前于黄河从黑鳍鳈进化而来。基于对黑鳍鳈的系统地理学分析，我们还认为，山脉隆起和水系隔离后的地理隔离在产生进化谱系分化中起重要作用。此外，分子年代测定估计黑侧条鳈的分化时间可追溯到0.95~3.92 Ma。失配分布分析和中性检验也表明黑鳍鳈种群近期经历了种群扩张，更新世气候变化的影响可能是黑鳍鳈种群动态的一个关键因素。
