3个中国地方黄牛品种遗传结构及其遗传分化的研究

Genetic Structure and Differentiation of Three Chinese Indigenous Cattle Populations

利用12对微卫星引物对中国3个地方黄牛品种(鲁西黄牛、渤海黑牛及闽南黄牛)及2个对照群体(中国荷斯坦牛和青海牦牛)的群体遗传结构、遗传分化及基因流水平进行研究,结合聚类分析,结果表明:5个牛群体总近交系数(Fit)为58.5%,群体内近交系数(Fis)为43.2%,群体间基因分化系数(Fst)为26.9%,3个指标均达到极显著水平(P<0.001)。5个牛群体内近交系数(Fis)鲁西黄牛最高(0.640),青海牦牛最低(0.231)。鲁西黄牛与荷斯坦牛间每世代群体间有效迁移个体数(Nem)最大(1.149),牦牛与鲁西黄牛间最小(0.509)。5个牛群体每个体属于所属群体的平均概率从91.4%到98.5%不等。结合聚类分析、基因流分析及STRUCTURE分析结果,5个牛群可分为3大类:鲁西黄牛和中国荷斯坦牛为一类,渤海黑牛和闽南黄牛为一类,牦牛自为一类,这说明在鲁西黄牛和渤海黑牛的形成过程中,鲁西黄牛受普通牛影响较大,而渤海黑牛受瘤牛影响较大,同时探讨了以上品种的演化与形成过程。

Using the information from 12 microsatellite to estimate level of genetic differentiation. gene flow and genetic structure of three indigenous cattle populations （Luxi, Bohai and Minnan） and two reference cattle populations （Chinese Holstein and Qinghai yak） in China. The global heterozygote deficit across of all populations （Fis） amounted to 58.5% （P〈0. 001）. The overall significant （P〈0. 001） deficit of heterozygotes because of inbreeding within breeds amounted to 43.2%. The five cattle populations were highly differentiated （Fst= 26.9%, P〈0.001） with all loci. The heterozygote deficit within population （Fis） was highest in Luxi cattle and lowest in Yak. The average number of effective migrants exchanged per generation （Nem） was highest （1. 149） between Luxi and Holstein, and lowest （0. 509） between Luxi and Yak. With the application of prior population information, cluster analysis achieved posterior probabilities from 91.4 to 98.5 % of correctly assigning individuals to their rightful populations. Combining the information of cluster analysis, gene flow and STRUCTURE analysis, five cattle populations belong to three genetic clusters, a taurine （Luxi and Chinese Holstein）, a zebu （Bohai and Minnan） and a yak cluster. This indicate that Bohai black have more blood of the Bos indicus than Luxi cattle. The evolution and development of three indigenous cattle populations were discussed in this article.