中国荷斯坦牛TLR2基因遗传多态性的研究

Analysis of Genetic Polymorphisms of TLR2 Gene in Chinese Holstein

以297头中国荷斯坦奶牛为研究对象,以TLR2(Toll like receptor 2)基因为目的基因,扩增目的片段,结合测序结果采用PCR-RFLP和CRS-RFLP技术方法来检测TLR2基因第2外显子的遗传多态性。结果发现:exon 2存在10098(T/G),10111(G/A)和11541(C/T)3个单核苷酸突变,其中11541位点的T/C突变为首次报道。分别选择EcoRV、HaeⅢ、DraⅠ等3种限制性内切酶检测其多态性。10098位点有3种基因型(AA,AB,BB),A、B等位基因频率分别为0.784 5,0.215 5;10111位点有2种基因型(CC,CD),C、D等位基因频率分别为0.9858,0.0142;11541位点有3种基因型(EE,EF,FF),E、F等位基因频率分别为0.0993,0.9007。10098位点T-G碱基突变导致天冬氨酸突变为谷氨酸(Asp63Glu),10111位点G-A碱基突变引起甘氨酸突变为丝氨酸(Gly68Ser)。TLR2基因外显子2上的3个位点基因型在研究群体中的分布均符合Hardy-Weinberg平衡定律(p>0.05)。10098,10111,11541 3个位点的多态信息含量、杂合度、有效等位基因数分别为0.2809/0.3381/1.5108,0.0279/0.0279/1.0287和0.1434/0.1789/1.2179。10098位点达到中度多态,其余2个位点处于低度多态。TLR2基因可作为候选遗传标记,进行深入研究。

The genetic ploymorphisms of 297 Chinese Holstein cows with family trees and production records were investigated by using PCR-RFLP and CRS-RFLP. Three mutational polymorphic sites, 10098 （ T/G）, 10111 （ G/A ） and 11541（C/T） ,were found in the TLR2 gene exon 2.The single nucleotide change at position 10098 and 10111 sites resulted Asp63Glu and Gly68Ser respectively. In the 10098 site there were three gene types AA, AB and BB, the allelic frequencies of A and B were 0.784 5 and 0.215 5 respectively. In the 10111 site there were two gene types CC and CD,the allelic frequencies of C and D were 0.985 8 and 0.01d 2 respectively. In the 11541 site there were three gene types EE, EF and FF,the allelic frequencies of E and F were 0.099 3 and 0. 143 4 respectively. Those three polymorphic sites in the TLR2 gene exon 2 were in accordance with the Hardy-Weinberg equilibrium（p 〉 0.05）. In the 10098 and 10111 and 11541 sites, the heterozygosity were 0.338 1,0.027 9 and 0.178 9 respectively, the number of effective alleles were 1.510 8,1.028 7 and 1. 217 9 respectively, the polymorphic information contents were 0. 280 9,0. 027 9 and 0. 143 4 respectively. The 10098 site was medium polymorphic and the other two sites were low polymorphic.