中国绵羊群体mtDNA D-Loop的遗传多样性分析  

Genetic diversity of Chinese domestic sheep using mitochondrial DNA D-loop

作　　者：成述儒[1] 韩建林[1] Olivier Hanotte 罗玉柱[1] 

机构地区：[1]甘肃农业大学动物科学技术学院,甘肃兰州730070 [2]国际家畜研究所,肯尼业内罗毕00100

出　　处：《甘肃农业大学学报》2005年第4期440-447,共8页Journal of Gansu Agricultural University

基　　金：国家科技攻关项目(2002BA901A29)甘肃省农牧厅项目(034050)甘肃省科技厅项目(033135)国际家畜研究所动物遗传资源项目(BT03)资助研究内容。

摘　　要：为了研究中国家养绵羊的起源和遗传多样性,通过对143只绵羊(9个群体)的线粒体DNA(mtDNA)D-环的部分序列进行PCR扩增,测序获得1个长度为723bp的序列(含5个75bp的重复单元),137个长度为648bp的序列(含4个75bp的重复单元)。5个长度为573bp的序列(含3个75bp的重复单元),因此认为含有4个重复单元是家养绵羊mtDNAD-环的特征,mtDNA序列长度的变异主要是由于重复区重复单元次数的不同造成。对137个含有4个重复单元的序列进行分析,发现157个变异位点,占研究位点的24.22%。A、T、G、C含量分别为35.67%、27.85%、13.84%和22.64%。137个序列共发现96个单倍型,单倍型比例为70.07%,说明中国家养绵羊具有丰富的mtDNAD-环序列多态性。96个单倍型序列的系统发育树呈现出3个明显的分支,网络分析也分为明显的三支,因此认为中国家养绵羊有3个母系起源。从Genebank获得的91个绵羊D-环序列和中国的96个绵羊D-环单倍型序列研究表明,摩佛伦(Mouflon)与单倍型B聚为一类,说明摩佛伦与中国家养绵羊具有很近的亲缘关系。没有发现羱羊(Ovisammonargali)、盘羊(O.vigneibochariensis)和东方盘羊(O.ammonnigrimontana)对中国和蒙古家养绵羊起源有贡献的证据。Part of mtDNA D-loop of 143 individuals （9 populations） were sequenced and analysed in order to investigate the origin and genetic diversity of Chinese domestic sheep. The amplified products were as follows： a 723 bp sequence （including 5 repeats of 75 bp）, 137 sequences of 648 bp long （including 4 repeats of 75 bp）, 5 sequences of 573 bp long （including 3 repeats of 75 bp）. Therefore, including 4 repeats was the character of domestic sheep mtDNA D-loop sequence. 96 haplotypes and 157 variations （24.22 %） were revealed in the 137 sequences. Analysis of phylogenetics of these 96 haplotypes showed that there were 3 obvious branches of Chinese domestic sheep, this indicated that Chinese domestic sheep had 3 maternal origins. The 96 haplotypes were compared with 91 sheep D-loop sequences from Genebank, the results showed that Mouflon and haplotypes B clustered together, this indicated that Mouflon had very close relation to Chinese domestic sheep. There was no evidence indicated that Ovis ammon argali, Ovis vignei bochariensis and Ovis ammon nigrimontana had any contribution to origin of Chinese domestic sheep.

关 键 词：绵羊 线粒体DNA D-环 遗传多样性 母系起源 

分 类 号：Q789[生物学—分子生物学]