黄河上游花斑裸鲤Cyt b基因的序列变异和遗传多样性  

Genetic Variation and Diversity of Gymncypris eckloni in the Upper Yellow River Inferred from Mitochondrial Cytochrome b Gene

作　　者：祁得林[1] 

机构地区：[1]青海大学农牧学院动物科学系,青海西宁810016

出　　处：《Zoological Research》2009年第3期255-261,共7页动物学研究（英文）

基　　金：国家自然科学基金(30860048);青海大学高层次人才项目资助

摘　　要：花斑裸鲤(Gymncypris eckloni)主要分布于黄河上游高原宽谷河段深水缓流处或静水湖泊中,在高原淡水生态系统的食物链中具有重要的地位。本文获得了黄河上游花斑裸鲤5个种群共68个个体线粒体DNA(mtDNA)细胞色素b基因的全序列(1140bp),分析了序列变异和种群遗传多样性。68个序列经比对后,发现30个(2.63%)多态性位点,共定义了18个单倍型。结果显示,花斑裸鲤种群单倍型多样度和核苷酸多样度均低于其它鲤科鱼类,这可能与青藏高原经所经历的地质变迁和古气候环境的改变有关,由此生活在高原水域中的鱼类或多或少经历过瓶颈效应。AMOVA分析结果显示,遗传差异主要发生在种群之内,而不是来自不同地理组群间或组群内种群间。单倍型网络图和系统发育分析均没有显示出单倍型与地理位置的对应关系,提示黄河上游花斑裸鲤自然种群未出现分化,应作为一个整体进行保护。单倍型歧点分布呈现为单峰以及中性检验Fu’sFs(-15.3400,P<0.001)和Tajima’sD(-0.6254,P=0.3080)结果综合表明,花斑裸鲤可能经历过近期的种群扩张事件。Gymncypris eckloni, being distributed mainly in the upper reaches of Yellow River and lakes in the Qinghai-Tibetan Plateau, plays significant roles in the trophic web of plateau freshwater communities. In the present study, the complete sequences of the mitochondrial Cyt b gene （1 140bp） from sixty eight individuals representing five populations from the upper Yellow River were obtained to assess the genetic variation and diversity. Within the aligned 1140 bp bases, 30 （2.63%） nucleotides were variable, and a total of 18 haplotypes were identified. The results showed that the haplotype diversity and nucleotide diversity of Gymncypris eckloni populations were low by comparison with the other species of family Cyprinidae, which maybe related to tectonic movements and paleoenvironmental fluctuations of the Qinghai-Tibetan Plateau, and that the populations have experienced bottleneck events in history. The AMOVA analysis indicated that the genetic variation mainly occurred within populations instead of among different geographic groups or among populations within among different geographical groups. There is no geographic clustering observed in the phylogenetic tree and the TCS network, which suggest that the natural populations of Gymncypris eckloni should be managed and conserved as a whole. The unimodal mismatch distribution of haplotypes, together with the selective neutrality test of Fu＇s Fs （-15.3400, P〈0.001） and Tajima＇s D （-0.6254, P =0.3080）, suggest that a recent population expansion of Gymncypris eckloni have been occurred.

关 键 词：花斑裸鲤 线粒体细胞色素B基因 遗传多样性 种群扩张 黄河 

分 类 号：Q953[生物学—动物学]