4个绵羊品种线粒体细胞色素b基因的序列差异和系统进化研究  

Study on Sequence Variation of Mitochondrial Cytochrome b Gene and Phylogenetic Relationships of Four Native Sheep Breeds

作　　者：张传生[1] 耿立英[2] 万海伟[2] 李吉涛[2] 杜立新[3] 

机构地区：[1]山东农业大学生命科学学院,泰安271018 [2]山东农业大学动物科技学院,泰安271018 [3]中国农业科学院畜牧研究所,北京100094

出　　处：《畜牧兽医学报》2005年第4期313-317,共5页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家自然科学基金项目(30270949);山东省自然科学基金项目(Y97D03062)

摘　　要：测定了小尾寒羊、大尾寒羊、洼地绵羊、滩羊和鲁北白山羊5个品种羊415bp线粒体DNA细胞色素b基因片段,其中44个位点检出变异。分析其碱基组成和变异情况,并以鲁北白山羊为外群,用UPGMA和NJ法构建了一系列分子系统树,得到相同的拓扑结构,在分子水平从母系遗传的角度澄清4个绵羊品种的起源分化关系。结果显示:在4个绵羊品种之间,洼地绵羊与滩羊关系最近与小尾寒羊亲缘关系最远。绵羊品种内的平均差异为0185%,线粒体DNA多态性相对贫乏,推测4个品种绵羊具有共同的母系祖先。The mtDNA Cyt b sequences(415 bp) were analyzed in four native sheep and one goat breeds (Little Tail Han sheep, Large Tail Han sheep,Wadi sheep,Tan sheep and Lubei White goat) in China.Base compositions and genetic distances among these regions were calculated and the homologous sequences were compared.Based on their Cyt b sequences the molecular phylogenetic tree was constructed by NJ and UPGMA method with the MEGA software.Furthermore,the phylogenetic relationship among the four sheep was discussed.The sequence alignment revealed considerable variation in 44 nucleotide sites.The value of average sequence variation in sheep population (π) is 0.85%.Our results suggest that the genetic diversity within the sheep is remarkably scarce and these sheep breeds may have originated from a late common ancestor. According to the phylogenetic tree,we suggest that Wadi sheep be more closely related with Tan sheep than other two sheep breeds.

关 键 词：线粒体细胞色素B基因 绵羊品种 系统进化 序列差异 线粒体DNA多态性 鲁北白山羊 小尾寒羊 洼地绵羊 分子系统树 UPGMA 大尾寒羊 基因片段 碱基组成 拓扑结构 起源分化 母系遗传 分子水平 亲缘关系 平均差 滩羊 变异 种羊 

分 类 号：S826.2[农业科学—畜牧学] Q959.842[农业科学—畜牧兽医]