岩羊不同种群细胞色素b基因序列差异的初步分析  

POPULATION GENETIC STRUCTURE OF BLUE SHEEP BASED ON MOLECULAR EVIDENCE FROM mtDNA

作　　者：曹丽荣[1] 王小明[1] 饶刚[2] 章克家[1] 万秋红[2] 方盛国[2] 

机构地区：[1]华东师范大学生命科学学院,上海200062 [2]国家濒危野生动植物种植基因保护中心

出　　处：《动物分类学报》2004年第4期633-638,共6页Acta Zootaxonomica Sinica

基　　金：国家自然科学基金资助项目 (39970 1 30 ) ;上海曙光计划资助项目;教育部骨干教师计划资助项目 ;上海市生态学重点学科 ;华东师范大学"十五""2 1 1工程"重点学科建设项目生态学项目;华东师范大学跨世纪优秀人才培养计划基金资助项目

摘　　要：测定了来自四川和宁夏两个种群的岩羊Pseudoisnayaur共 10个个体的线粒体DNA细胞色素b基因全序列(114 0bp) ,分析了碱基组成和变异情况以及核苷酸序列差异 ,计算了岩羊种群的核苷酸多样性 ,采用简约法和距离矩阵法构建了不同的分子系统树 ,得到了相似的拓扑结构 ,从分子水平初步探讨了岩羊不同种群的遗传结构。结果显示 :岩羊整个群体的遗传多态性较高 ,四川种群的遗传变异水平较宁夏种群的高 ;同时 ,四川种群岩羊个体之间的平均序列差异为 2 15 ,宁夏种群岩羊个体之间的平均序列差异为 0 71,四川种群和宁夏种群之间的序列差异为2 6 1,这反映了四川种群和宁夏种群种群内的差异以及四川种群和宁夏种群种群间的差异都属于个体间的变化 ;然而四川种群的个体 11(Si11)与该种群内的其它个体的平均序列差异和平均Kimura两参数距离远高于它与宁夏种群个体间的相应数值 ,存在着较为明显的分歧。形成这一现象的原因可能要涉及到岩羊在中国的地理演化和扩散问题。Blue sheep(Pseudois nayaur)is registered in the state key protected wildlife list as CategoryⅡspecies and is widely distributed in most areas of South-west and North-west of China. There has been no previous molecular examination of population genetics structure. Consequently, the author used mtDNA Cyt b sequence as genetic marker to resolve the population genetic structure of Bharal. Total DNA of ten dried skin samples of Bharal from Sichuan and Ningxia Provinces in China was extracted and sequenced. Based on the complete Cyt b gene sequence(1140bp)from these samples, the author aligned them with the program of Clustal W. Ten complete sequences from blue sheep were deposited in GenBank(accession numbers: AF493575—AF493580,AF473606,AF473607,AF500196,AF500197). By pair-wise comparison, Kimura 2-parameter distance and base substitution among these sequences were analyzed with the MEGA software package. Accordingly, the base composition of blue sheep showed the same character as that of other mammals. Simultaneously, nucleotide diversity and gene flow between two populations were calculated by DNAsp software package. The phylogenetic trees constructed by multiple methods(NJ and MP)supported almost the same topology, in which Ningxia lineage contained Si11 from Sichuan population,with branch nodes also well supported by bootstrap analysis. However, that was not concordant with geographical partitioning. Our molecular results showed Sichuan population of blue sheep had higher genetic diversity than Ningxia population. The mean sequence divergence in Sichuan population, Ningxia population and between them were 2.15,0.71,2.61, respectively. In the meantime, 2.63 between Si11 and the others of Sichuan population, 0.93 between Si11 and all Ningxia individuals, which reflected deeper evolutionary seperation existed in the former than in the latter. Pleistocene range expansion and dispersal from refugial populations exerted great influence on genetic structure within this species. There was little biological basis fo

关 键 词：岩羊 种群 序列差异 细胞色素B基因 分子系统树 碱基 遗传结构 遗传变异 个体 群体 

分 类 号：Q953[生物学—动物学]