鲁西黄牛和渤海黑牛MRF家族基因编码区DNA多态性分析

DNA polymorphism in the coding-region of MRF family genes of Chenese Luxi and Bohai cattle breeds

由鲁西黄牛和渤海黑牛主要产区随机采集牛颈静脉血样,采用酚-氯仿法提取基因组DNA,用覆盖基因序列全长的15对引物扩增MRF家族4个基因MyoD、MyoG、Myf5和Myf6并测序,应用相关分子生物学软件对测序结果进行分析,以揭示其DNA多态性。通过对154条序列测序、比对,共发现36个核苷酸突变位点,其中7个位点与已报道的相同,29个为鲁西黄牛和渤海黑牛所特有,简约信息位点26个。这些突变位点大多发生在内含子和UTR序列,CDS序列的组成和结构比较稳定。在MFR家族的4个基因中,MyoG核苷酸变异程度最高,Myf6最低。2个黄牛群体的单倍型多样性程度较高,鲁西黄牛群体DNA多态性高于渤海黑牛。结果提示2个地方黄牛群体含有丰富的遗传变异信息,对应用分子标记辅助选择技术培育中国特有肉牛品种具有重要的参考价值。

The jugular vein bloods of individual Luxi and Bohai cattle were collected with random sampling methods from the major local raising areas.The DNAs were extracted with phenol-chloroform method.15 pairs of PCR primers,which approximately cover the whole length of each of the four MYF family genes（MyoD,MyoG,Myf5 and Myf6） were used for amplifying the genes,and the PCR products were-sequenced-after being tested by agr-gel.Then,the-sequences-were analyzed by some molecular biologic softwares.36 potential mononucleotide mutational sites were identified from the 154 PCR fragments of MRF family genes.Among them,7 sites were shared with the similar research reported,and 29 sites were first identified in Luxi and Bohai breeds,and 26 had parsimony informative sites.Most of the mononucleotide mutational sites were identified in introns and UTR.The composition and structure of CDS were relatively stable.The results demonstrate that among the 4 genes of MFR,the MyoG shows the highest DNA polymorphism.There are relatively high level of haploid diversity of MRF family genes in Luxi and Bohai cattle populations,and the DNA polymorphism in Luxi is richer than that of in Bohai cattle.This implicates that the two native cattle breeds have rich information of genetic variation.It might provide a tool of applying molecular marker-assisted-selection-in breeding for developing the Chinese specific beef cattle breeds.