德昌水牛Bola-DRB3基因第二外显子的PCR-RFLP多态性研究

Study on the Polymorphism of the Bola-DRB3 Gene exon 2 in Dechang Buffalo by the PCR-RFLP Method

本研究应用PCR-RFLP方法,对德昌水牛MHCⅡ类基因座位的Bola-DRB3基因第2外显子进行了遗传多态性研究。结果表明:HaeIII酶切出现7种基因型,即AA、AB、AD、BC、AC、BF和BB,共有A、B、C、D、F 5个复等位基因控制;AA型的频率最高,为优势基因型,A基因为优势基因。RsaI酶切结果出现3种基因型,即GH、GG、HH,共有G、H 2个基因控制;GG的频率最高,为优势基因型,G基因为优势基因。这表明德昌水牛在Bola-DRB3基因第2外显子上具有丰富的多态性。在RsaI酶切位点上,德昌水牛未达到Hardy-Weiberg平衡状态,显示在群体中有选择、基因突变、近交、遗传漂变等因素的一定影响,这是对保种极为不利的,应引起畜牧工作者的关注。在德昌水牛遗传资源的开发利用和保存中,作者认为应严格划定杂交改良和保种区的范围;在杂交改良区内可以进行选育、品种间杂交,充分利用杂种优势,提高其生产性能;而在保种区或群中不进行杂交,同时减少选育;使德昌水牛遗传资源的有效保存和充分利用有机的结合起来。

The PCR-RFLP method was applied to study the genetic poly morphism of Bola-DRB3 exon 2on MHCⅡ of Dechang cattle. The results showed that there were 7 genotypes in HaeⅢ ,ie AA,AB,AD, BC, AC,BFand BB, controlled by 5 allelic genes, A, B, C, D and F; among which AA had the highest frequency, and as a sesuh,it was the preponderant gene type, and A was the preponderant gene. There were 3 genotypes in Rsa I ,ie GH,GG,HH,controlled by G and H genes; in which GG had the highest frequency, and was the preponderant gene type,and G was the pre ponderant gene, This shows that Dechang cattle has rich polymoprphism on Bola-DRB3 exon 2. On the restricion enzyme cutting site of RsaI,Dechang cattle reached Hardy-Weiberg balance, indicating the influences of such factors as selection, gene mutation,close breeding and genetic drift,which is unfavorable to breed keeping and should be attached importance to. The author thinks that crossbreed improvement and breed keeping area should be strictly defined so as to make full use of the prons of crossbreed and improve their productive performance, thus effectively keeping the genetic vesources of Dechang cattle and making good use of it.