中国南方部分黄牛品种mtDNA D-loop区的遗传变异与分类分析

The analysis of genetic variation of mtDNA D-loop region and phylogenesis on some southern Chinese cattle breeds

【目的】检测中国黄牛品种的遗传多样性和遗传亲缘关系。【方法】扩增、测序并分析了8个南方黄牛品种(川南牛、务川牛、温岭牛、隆林牛、湘西牛、郧巴牛、昭通牛、锦江牛)共计40个个体的线粒体D-loop区(mtDNAD-loop)全序列。【结果】共检测到56个变异位点,17个单倍型,平均核苷酸差异(K)为20.364,核苷酸多样度(π)为2.25%,单倍型多样度(Hd)为0.750±0.074;4种碱基A、T、C、G的频率分别为33.2%,28.2%,25.1%和13.5%;56处多态位点中,转换49处(占多态位点87.5%),颠换4处(占7.14%),缺失/插入3处(占5.36%);在样本数量超过3的群体中,锦江牛和昭通牛分别显示出最贫乏和最丰富的遗传多样性;构建的NJ进化树表明,云南昭通牛与其他7个品种的亲缘关系最远。【结论】普通牛较瘤牛具有丰富的遗传多样性,支持普通牛的多地区起源说;云南昭通牛含有不同于印度瘤牛的瘤牛血统,从分子水平上支持云南是潜在的瘤牛起源驯化中心。

[Objective] The study was to detect the genetic diversity and relationship of cattle in south China. [Method] The complete mitochondrial control regions of 40 cattle in 8 breeds were sequenced and analyzed. [Result] The results showed as follows.. 56 variations and 17 haplotypes were detected, average number of nucleotide differences （K） was 20. 364,nucleotide diversity （zr） 2.25% ,and haplotype diversity （Hd） 0. 750±0. 074. The frequencies for the A,T,C,G bases were 33.2%,28.2%,25.1% and 13.5% respectively. Among the 56 variations,there were 49 transitions,4 transversions,and 3 insertion/deletion. Jinjiang cattle and Zhaotong cattle showed the most spare and aboundant genetic diversity. The NJ tree constructed from the genetic distance displaied the most remote relationship for Zhaotong cattle. [Conclu-ion]B. taurus had far more aboundant genetic biodiversity than B, fndfcus which supported multi-regional origin. And Zhaotong cattle showed a different B. indicus type to India B. indicus type. This indicated a potential origin region for B. indicus at molecular level.