作　　者： ; ; ; ; ; ;

机构地区： 华南农业大学动物科学学院

出　　处： 《上海海洋大学学报》 2012年第3期337-343,共7页

摘　　要： 利用PCR技术扩增得到珠江和长江水系共29个赤眼鳟(Squaliobarbus curriculus)线粒体DNA D-loop基因片段,并测定其序列。对599 bp的D-loop基因序列进行分析,共检测到24个单倍型,25个单突变位点,39个简约信息位点。在81个突变位点中,转换位点50个,颠换位点14个,插入或缺失位点17个;A+T的含量(68.8%)明显高于C+G的含量(31.2%)。5个水域个体间的遗传变异率在0到6.03%之间。单倍型多样性(H)为0.977 8,平均核苷酸差异数(K±SD)为17.271 0,核苷酸多样性(π)为0.029 7。对5个群体D-loop序列进行分化指数分析,结果表明:不同水系群体间有显著的遗传差异,而同一水系内的不同群体间差异不显著。对5个群体进行分子方差分析,结果表明:5个群体间存在显著性遗传差异。分子系统树显示:两大水系5个不同水域赤眼鳟29个个体的系统树明显分为两支:珠江15个个体聚为一支,长江14个个体聚为另一支,且都有较高的置信度。可见,长江和珠江群体间已经出现了明显的遗传变异,是因珠江和长江的地理隔离导致的生殖隔离。但在同一水系内,群体间的遗传距离和群体内的遗传差异不显著,系统树也是两大水系内的不同水域混杂在一起,说明同一水系不同水域间没有出现遗传分化,分属"长江群体"或"珠江群体"。 29 mitochondrial D-loop gene segments of Squaliobarbus curriculus from Yangtze River and Pearl River were amplified with PCR technique and sequenced. Analysis on D-loop of 599 bp showed that there were 24 unique sequences, 25 singleton, 39 parsim-info, 81 mutation sites in all, including 50 transition sites, 14 transversion sites and 17 insert/lacuna sites. The content of A ＋T （68.8%） was much more than that of C ＋ G （31. 2%）. The genetic diversities among the 5 water areas ranged from 0 to 6. 03%. Haplotypic diversity（H） was 0. 977 8, mean number of pairwise differences （ K ＋ SD ） was 17. 271 0, nucleotide diversity （w） was 0. 029 7. FST values between WH and SS, XF, WZ populations, between YC and SS, XF, WZ populations showed significant genetic differences, and the one among all the other populations showed no strong genetic differences. Significant genetic differentiation among all five populations was found by analysis of molecular variance （AMOVA）. According to the molecular phylogenetic tree constructed by NJ methods based on D-loop, the individuals of Yangtze River and Pearl River assembled in two branches respectively with high confidence. The obvious genetic differentiation was mainly attributed to the reproductive isolation caused by the geographical isolation between Yangtze River and Pearl River. But, for Yangtze River, the molecular phylogenetic tree was immingled because the intrapopulation and interpopulation genetic distances differed little. So it showed that there was no genetic differentiation in those from different water areas, which belonged to ＇Yangtze population＇. It was also the case with ＇Pearl population＇.

关 键 词： 赤眼鳟 线粒体 遗传变异 珠江 长江

领　　域： [农业科学]