中国绵羊群体Fec^B基因遗传分化的研究

Study on genetic differentiation of Fec^B gene in Chinese sheep population

为研究我国绵羊各地区Fec^B基因的遗传多样性,笔者采用PCR-SSCP和PCR-RFLP方法对苏州湖羊、徐州湖羊、小尾寒羊、洼地绵羊、阿勒泰羊和中国美利奴绵羊的Fec^B基因座位进行了检测,引用其他绵羊品种资料辅助分析,并计算其平均杂合度,对其中立性测验的结果进行了相关分析。结果表明:(1)6个绵羊群体的Fec^B座位基因分化系数Gst=0.2937,说明有70.63%的变异是由群体内的遗传多态现象引起,而只有29.37%的变异来自群体间变异。(2)中立性检测的观察值均在L95和U95之间,表明Fec^B位点为中立性位点,其遗传多样性基本上未受选择等因素的影响。(3)Fec^B基因在地理分布上存在一定的规律,东部绵羊品种Fec^B的基因频率高于西部,东部由北向南依次递加。

For research on the genetic diversity of FecB gene of sheep from regions of China, PCR-SSCP and PCR-RFLP methods were adopted to detect the FeeB locus in Su Zhou Hu sheep, Xu Zhou Hu sheep, Small Tailed Han sheep, Wadi sheep, Ahai sheep and Chi- nese Merino sheep, and reference data of other sheep breeds to analysis. Then, the average heterozygosity of Fees locus was calculated and the result of neutrality test was correlated. The results of PCR-SSCP and PCR-RFLP proved that the coefficient of Fecs locus differ- entiation between these six sheep groups is Gst=0.2937, which indicated that 70.36% of variations of FecB locus in the 6 populations were caused by genetic polymorphism within populations and only 29.37% due to the difference among populations. The observed values of the neutrality test were between L95 and U95, which indicated that Fees gene- locus is a neutrality gene- locus and the genetic diver- sity is almost not affected by the selection and other factors. There was regulation in the geographical distribution of FecB genes, which was showed as the frequency of FecB gene in the eastern sheep breeds was higher than that in the western region and in the eastern region from north to south in order of increasing.