长江上游长薄鳅Cytb基因的序列变异与遗传结构分析  

Sequence Variability of Cytochrome b and genetic structure of Leptobotia elongata in the upper Yangtze River

作　　者：田辉伍[1,2] 段辛斌[2] 汪登强[2] 刘绍平[2] 陈大庆[2] 

机构地区：[1]西南大学生命科学学院淡水鱼类资源与生殖发育教育部重点实验室,重庆400715 [2]中国水产科学研究院长江水产研究所,武汉430223

出　　处：《淡水渔业》2013年第6期13-18,28,共7页Freshwater Fisheries

基　　金：中国长江三峡集团公司资助项目(No.0799527;No.0714097);公益性行业(农业)科研专项经费(No.200903048);国家自然科学基金(No.51249004)

摘　　要：采用线粒体DNA序列对长江上游长薄鳅(Leptobotia elongata Bleeker)长江干流、岷江、赤水河和嘉陵江的8个群体176尾样本的遗传结构进行了分析,长薄鳅cyt b基因序列分别检出了25个变异位点和25个单倍型,单倍型多样性(H d)和核苷酸多样性(π)分别为0.608 52和0.000 89。单倍型网络结构图和N J树均未显示与地理种群相关的信息。分子变异方差分析结果表明长薄鳅种群内的变异大于种群间的变异,变异主要来自种群内部,群体遗传分化不显著(F st<0.05),种群基因交流十分频繁(N m>1)。中性检验值(Tajima's D=-2.279 09,P<0.01;Fu and Li's D*=-4.670 47,P<0.02;Fu and Li's F*=-4.470 16,P<0.02)和单倍型错配分布结果显示长薄鳅经历了最近的种群扩张事件。In this study, 176 specimens of Leptobotia elongata were collected from 8 sample sites in the upper Yangfze River for the genetic structure analysis. With the utilization of mitochondrial DNA analysis, 25 variable sites and 25 haplotypes of L. elongata were detected by Cyt b gene sequences. Haplotype diversity （Hd ） and nucleotide diversity （7r） were 0. 608 52 and 0. 000 89, respectively. Haplotype network structure and NJ molecular phylogenetic tree of L. elongata were not sharp branch or geographic populations. Hierarchical analysis of molecular variance （AMOVA） of cyt b gene sequence among and within populations revealed no significant genetic structuring among populations and variation were mainly within the population. Also, there was no significant genetic differentiation （ F^st 〈 0. 05 ） , and estimates of gene flows among groups were high（Nm 〉 1 ）. Significant values （Tajima＇s D = -2. 279 09（P 〈0.01 ） , Fu and Li＇s D^＊ = -4. 670 47（P 〈 0. 02）, Fu and Li＇ s F^＊ = - 4. 470 16 （ P 〈 0. 02 ） ）, together with uni-modal mismatch distribution indicated that L. elongata had experienced recent population expansion.

关 键 词：长薄鳅(Leptobotia elongata) 遗传结构 长江上游 

分 类 号：S917.4[农业科学—水产科学]