中华鳖3个地理群体线粒体基因D-loop区遗传多样性分析  

The genetic diversity of mitochondrial DNA D-loop region of three geographical populations in Trionyx sinensis

作　　者：黄雪贞[1,2] 钱国英[2] 李彩燕[2] 

机构地区：[1]上海海洋大学水产与生命学院,上海201306 [2]浙江万里学院生物与环境学院,浙江宁波315100

出　　处：《水产学报》2012年第1期17-24,共8页Journal of Fisheries of China

基　　金：浙江省农业科技重大攻关项目(2006C12011)

摘　　要：采用PCR结合DNA测序技术和SSCP技术,分析了中华鳖3个地理群体线粒体DNA(mtDNA)D-loop区部分序列的变异及遗传多样性。在25个个体中,其碱基组成为A+T的平均含量(65.4%)高于G+C(34.6%),共检测到变异位点7个(约占总位点数的5.7%),转换/颠换值为2.76。核苷酸多样性(π)为0.019 95,平均核苷酸差异数(K)为2.453。25个个体分属6个单倍型,单倍型多样度(Hd)为0.707,单倍型间的平均遗传距离(P)为0.027。6个单倍型构建的UPGMA系统树聚为3个分支。结果表明,中华鳖群体mtDNA D-loop区序列存在着较丰富的变异和遗传多样性,日本鳖的遗传多样性比黄河鳖和黄沙鳖丰富,黄沙鳖与日本鳖、黄河鳖的遗传距离较远。而且PCR-SSCP可以检测到两种类型的电泳图谱,其中Ⅱ型均为日本鳖,该技术可用于78位TT←→AA颠换变异位点的检测。Trionyx sinensis is regarded as a very important fishery animals with high economic value.However,the germplasm resources of Trionyx sinensis are exposed to admixture and degeneration due to the booming industry.The investigation of genetic diversity of Trionyx sinensis is beneficial to protect the germplasm resources.In the present study,the variation and genetic diversity of mtDNA D-loop region partial sequences in three geographical populations of Trionyx sinensis were analyzed by PCR combined with DNA sequencing and SSCP techniques.The average contents of A＋T（65.4%）were higher than that of G＋C（34.6%）.A total of 7 variable sites（about 5.7% of the total nucleotides in the sequence）were detected in 25 individuals,and the value of si/sv was 2.76.The nucleotide diversity（π）of the 25 individuals was 0.019 95,and the average number of nucleotide differences（K） of them was 2.453.The 25 individuals belonged to 6 haplotypes according to the determined sequences.The haplotype diversity（Hd）was 0.707,and the average genetic distance（P） among the haplotypes of the species was 0.027.The analysis of phylogenetic tree with the method of UPGMA showed that the 6 haplotypes were clustered into three groups.Our data indicated that the variation and genetic diversity were high in the three populations of T.sinensis,in which the genetic diversity of Japanese population was richer than that of Huanghe and Huangsha population,and the genetic distance between Huangsha population and the other two populations was far.Moreover,we found that two types of electrophoretic patterns could be detected by PCR-SSCP,and all type Ⅱwere Japanese population,suggesting the effective application of PCR-SSCP method in 78 TT AA transversion mutation sites testing.

关 键 词：中华鳖 线粒体DNA D-LOOP区 遗传多样性 PCR-SSCP 

分 类 号：Q347[生物学—遗传学] S917[农业科学—水产科学]