基于细胞色素b基因的中国岩羊不同地理种群遗传差异分析  

Genetic diversity based on cytochrome b gene analysis of different geographic populations of blue sheep in China

作　　者：李楠楠[1] 刘振生[1,2] 王正寰[3] 黄丽红 

机构地区：[1]东北林业大学野生动物资源学院,哈尔滨150040 [2]国家林业局野生动物保护学重点实验室,哈尔滨150040 [3]华东师范大学生命科学学院,上海200062 [4]宁夏平罗县动物卫生监督所,平罗753400

出　　处：《生态学报》2012年第8期2381-2389,共9页Acta Ecologica Sinica

基　　金：国家新世纪优秀人才支持计划资助项目(NCET-08-0753);国家自然科学基金资助项目(30970371);中央高校基本科研业务费专项资金资助项目(DL09CA03);宁夏回族自治区林业局自选项目(2011-017)

摘　　要：为了揭示中国岩羊不同地理种群的遗传差异,探讨岩羊亚种分化的分子机制,采用中国岩羊不同地理种群的细胞色素b(Cyt b)基因的全序列,分析了碱基变异情况、遗传距离以及核苷酸序列差异。用最大似然法和贝叶斯法构建分子系统树并对获得的拓扑结构进行分析。结果发现,西藏亚种与四川亚种Cyt b基因平均序列差异为4.2%(±0.007),处于偶蹄目亚种的序列差异范围内,支持了目前对岩羊西藏亚种的分类地位。四川亚种内部各地理种群之间的遗传距离(0.033±0.0 111)与它们分别到西藏种群的遗传距离(0.042±0.007)差异不显著(t=1.824,P=0.084),说明四川亚种内部各地理种群间已经发生较显著的遗传分化。其中,四川、甘肃和青海种群亲缘关系较近,并与四川亚种内部的其它种群已产生了显著的遗传分化。因此认为四川亚种内部各地理种群的种下分化需要深入研究。Blue sheep（Pseudois nayaur） are endemic to the Tibetan Plateau and surrounding mountain regions.They are classified as Least Concern in the IUCN Red List of Threatened Species and are included in the list of the second grade nationally protected animals of China.Traditionally,blue sheep in China were classified into two subspecies,the nominate or Tibetan subspecies（P.n.nayaur） which is distributed on the Tibetan Plateau,and the Sichuan subspecies（P.n.szechuanensis） which has a widespread geographical distribution in the western and north-western areas of China.Different geographically distributed populations of the Sichuan subspecies are also found on several isolated mountains in China.Because of the lack of research data,the genetic validity and geographic characteristics of these two subspecies remain unclear.In the present study,we have sequenced the complete mitochondrial DNA cytochrome b（Cyt b） gene from tissue samples of blue sheep originating from seven distinct geographical populations（Qinghai,Sichuan,Gansu,Inner Mongolia,Ningxia,Xinjiang,and Tibet） covering all regions in which the sheep are distributed.Our aim was to measure the genetic divergence among these populations,and to analyze the base variation,genetic distance,and nucleotide sequence variability between the different populations.A total of 45 haplotypes from 59 cyt b gene sequences were identified.Only one of these haplotypes was shared by individuals from the Ningxia and Inner Mongolia populations.A maximum likelihood tree and a Bayesian tree were established using the Kimura2-parameter model to evaluate the genetic distance between samples from each pair of different geographical populations.We found that the genetic distances between the Tibetan populations（nominate subspecies） and the other geographical populations（Sichuan subspecies） were on average,4.2%（±0.007）.This value is higher than the average level of Cyt b sequence divergence among the different populations from the Sichuan subspecies and higher

关 键 词：岩羊 细胞色素B 遗传差异 种下分化 

分 类 号：Q346[生物学—遗传学]