用mtDNA D-环序列探讨蒙古和中国绵羊的起源及遗传多样性  

Origin and Genetic Diversity of Mongolian and Chinese Sheep Using Mitochondrial DNA D-loop Sequences

作　　者：罗玉柱[1] 成述儒[1] Batsuuri Lkhagva D.Badamdorj Olivier Hanotte 韩建林[1] 

机构地区：[1]甘肃农业大学动物科学技术学院,兰州730070 [2]蒙古国立农业大学 [3]蒙古畜牧研究所 [4]国际家畜研究所,肯尼亚内罗毕00100

出　　处：《Acta Genetica Sinica》2005年第12期1256-1265,共10页

基　　金：国家科技攻关项目(编号:2002BA901A29);甘肃省教育厅项目(编号:050203);甘肃省农牧厅项目(编号:GNSW200405);甘肃省科技厅项目(编号:033135);国际家畜研究所(ILRI)动物遗传资源项目(由英国;日本;欧盟;爱尔兰和法国资助)~~

摘　　要：为了在分子水平上探讨绵羊的起源,对中国和蒙古共20个绵羊群体、314只绵羊mtDNAD环的部分序列进行了测定。结果表明:中国绵羊和蒙古绵羊mtDNAD环区的部分序列中A、T、G、C含量没有明显的差别;蒙古绵羊的多态位点数(26.85%)略高于中国绵羊(24.22%);中国绵羊群体的单倍型多样度在青海藏羊、甘肃藏羊、甘肃高山细毛羊、青海细毛羊、甘南藏羊、小尾寒羊和滩羊群体中较高,但在湖羊和岷县黑裘皮羊中较低;蒙古绵羊的单倍型多样度在Bayad和Baidrag群体中最高,但在GobiAltai群体中最低。从总体上看,蒙古绵羊的遗传多样性要略高于中国绵羊,例如单倍型比例的平均值为86.06%(142/165)∶78.83%(108/137),单倍型多样度(Hd)的平均值为0.976∶0.936,核苷酸多样度(Pi(π))的平均值为0.036∶0.034,平均核苷酸差异数(k)的平均值为23.50∶22.46。217个中国和蒙古绵羊的单倍型序列的系统发生分析表明,中国和蒙古绵羊均有3个母系起源,被定义为A、B和C3类主要的单倍型。其中A类单倍型在所有中国绵羊群体及绝大多数蒙古绵羊群体(9/11)中占优势,平均比例为58.73%;B类单倍型居中,为24.68%;C类单倍型最少,仅为16.59%。进一步从GenBank获得的91个绵羊D环区的序列与中国和蒙古绵羊D环区的单倍型的进行网络关系分析,发现欧洲摩弗仑羊(Europeanmouflon,O.musimon)与中国和蒙古绵羊具有较近的亲缘关系,但没有发现羱羊(Argali,O.ammon)、盘羊(O.vigneibochariensis)和东方盘羊(O.ammonnigrimontana)对中国和蒙古绵羊起源有贡献的证据。To determine the origin and gene diversity of the Chinese and Mongolian domestic sheep, a partial fragment of mitochondrial DNA D-loop was sequenced for total number of 314 individuals from nine Chinese sheep populations and 11 Mongolian sheep populations. The results show no difference in nucleotide composition between Chinese and Mongolian sheep mtDNA D-loop sequences. However,more variables were identified in Mongolian sheep （26.85% of the sites） than that in Chinese sheep （24,22%）. In China,mtDNA haplotype diversity was the highest in Qinghai Tibetan sheep,followed then by Gansu Tibetan sheep,Gansu Alpine Merino,Qinghai Merino,Gannan Tibetan sheep, Small-tailed Han sheep,Tan sheep, Hu sheep and Minxian Black Fur sheep. In Mongolian sheep, mtDNA haplotype diversity was the highest in Bayad and Baidrag populations and the lowest in the Gobi-Altai population. In general, Mongolian sheep have a richer genetic diversity than the Chinese ones with larger number of haplotypes （86, 06% （142/165） versus 78.83% （108/137）） ,higher hap- Iotype diversity （Hd;O. 976 versus 0. 936 ）, higher nucleotide diversity （ Pi （π） ;0. 036 versus 0. 034 ） and higher average number of nucleotide differences （ k;23, 50 versus 22.48）. Phylogenetic analysis of the 217 haplotypes identified in both Mongolian and Chinese sheep supported the same origin of their domestication with three distinct maternal lineages defined as major haplotypes A,B and C,of which haplotype A are the commonest in all Chinese sheep populations and in the majority of Mongolian sheep populations （9/11 ） with an average frequency of 58. 73% ,followed by haplotype B present in eight of Chinese population and in all Mongolian sheep populations with an average frequency of 24.68%, and haplotype C present in eight Chinese and in 10 Mongolian sheep populations with an average frequency of 16.59%, Further network analysis of the phylogenetic relationship of the 87 haplotypes identified from 91 sequences retrieved from GenBank togethe

关 键 词：MTDNA D-环 绵羊 起源 遗传多样性 蒙古 中国 

分 类 号：S826[农业科学—畜牧学]