洼地绵羊MHC-DRB1基因PCR-RFLP多态性分析

Polymorphism Analysis of MHC-DRB1 Gene in Wadi Sheep by PCR-RFLP

为了探讨洼地绵羊MHC-DRB1基因的多态性,采用套式PCR扩增82只洼地绵羊的MHC-DRB1基因第2外显子,其296 bp扩增产物经SacⅠ、HaeⅢ限制性内切酶酶切后进行RFLP多态性分析。结果表明,洼地绵羊的MHC-DRB1基因外显子2在SacⅠ、HaeⅢ的酶切位点存在多态性,测序发现,这些酶切位点分别受2、5个等位基因控制,由于MHC-DRB1为多碱基突变的基因位点,综合2种限制性内切酶的酶切结果,在洼地绵羊中共发现15种基因型,其中新的等位基因MHC-DRB1.D(225 bp/71 bp)仅在该洼地绵羊群体中发现。对MHC-DRB1的5个等位基因的核苷酸序列以及预测的氨基酸序列分别进行比对,发现5个等位基因间存在丰富的变异位点。

To investigate the polymorphism of major histocompatibility complex ⅡDRB1（MHC-DRB1） in Wadi sheep,the second exon of this gene in 82 Wadi Sheep was amplified by nested PCR and the amplified products were characterized by RFLP technique using 2 restriction enzymes,ie,SacⅠandHaeⅢ.The results showed that the extensive polymorphisms of the exon2 of MHC-DRB1 were found at two loci digested with SacⅠandHaeⅢ,respectively,and these sites were controlled by two,five alleles,respectively.As some base mutations were found in MHC-DRB1locus,and according to the results in this paper,fifteen genetypes were found in Wadi sheep.The new allele MHC-DRB1.D was identified only in these Wadi sheep populations.The nucleotide and predicted amino acid sequence alignments of MHC-DRB1 alleles provided the evidence for considerable variation among the five alleles.