海南岛及邻近陆地拟细鲫的种群遗传分化和亲缘地理过程

为了解海南岛及邻近陆地拟细鲫(Aphyocypris normalis)的遗传分化和亲缘地理过程,采用线粒体细胞色素b(Cyt b)对9个种群共124个个体的遗传多样性和遗传分化进行评估,并探讨这一物种的亲缘地理结构及演化历史.结果显示,在1 140 bp的序列中,共检测到87个核苷酸变异位点,定义了34个单倍型.基于...

Population genetic structure and phylogeography of Aphyocypris normalis on Hainan island and its neighboring regions

To understand the genetic differentiation and phylogeography of Aphyocypris normalis on Hainan Island and its neighboring regions, 124 individuals from nine populations in nine drainage basins(Changhua, Lingshui, Wangquan, Nandu, Moyang, Jianjiang, Fangcheng, Beilun, and Pearl Rivers) were analyzed using mitochondrial DNA cytochrome b(Cyt b). The results showed that 87 polymorphic sites were detected, and 34 haplotypes were defined in all Cyt b sequences. Phylogenetic trees based on the Cyt b sequences comprised three major lineages(A, B, and C). Lineage A consisted of most populations from Hainan Island and all populations from its neighboring regions. All individuals from the Changhua River formed an independent lineage B. Lineage C was formed by all individuals from Shang’an Village(Wanquan River). The Fst among the lineages was higher(0.707 5-0.971 9). The divergence time of lineage C was 2.038 million years ago, and lineage B originated 0.865 million years ago. The demographic history showed that there was no expansion in most populations, and all lineages had recently experienced an effective population reduction. According to the results, it is speculated that the differentiation between the three lineages A, B, and C resulted from the uplift of the Yinggeling and Wuzhishan Mountains. However, most of the populations from Hainan Island and its neighboring regions were not differentiated. This could be because of the connection between Hainan Island and its neighboring regions caused by the fluctuation of sea level during the Pleistocene glacial period, resulting in gene flow between A. normalis populations on both sides of the Qiongzhou Strait. Based on these findings, we conclude that the Qiongzhou Strait did not act as a geographical barrier during the dispersion of A. normalis, and Hainan Island is the center of origin of the species.