GH和GHR基因多态性与滩羊生长性状的关联分析

Association analysis of the polymorphisms of the GH and GHR genes with the growth traits in Tan sheep

为了解滩羊生长发育的遗传机制,寻找与生长性状相关的分子标记,试验采用PCR-RFLP方法检测宁夏滩羊GH和GHR基因的多态性,分析了多态位点不同基因型及合并基因型与滩羊生长性状的关联性。结果表明:GH基因第2内含子和GHR基因第4外显子分别经PvuⅡ和HpaⅡ酶切各产生BB(0.375 0)、AB(0.625 0)和DD(0.825 0)、CD(0.175 0)2种基因型;GH基因PvuⅡ位点的不同基因型个体初生重和6月龄体重差异显著(P<0.05),与断奶重差异极显著(P<0.01),AB为优势基因型;GHR基因HpaⅡ位点的CD基因型初生重和6月龄体重显著高于DD基因型(P<0.05),而这两种基因型与断奶重差异不显著。对这两个SNPs位点进行基因互作分析发现双杂合基因型个体各生长性状均显著高于其他基因型组合(P<0.05),并且多标记位点的组合效应高于单标记位点。说明ABCD是影响滩羊生长性状的最佳基因型组合,可作为滩羊生长性状的遗传标记。

To understand the genetic mechanisms of growth and development, in Tan sheep, and search the molecular markers correlated with growth traits. A PCR- RFLP method was used to detect the polymorphisms of the growth hormone （GH） and growth hormone receptor （GHR） genes in Ningxia Tan sheep, thereby analyzing the association of the different genotypes and combined genotypes from polymorphic loci with the growth traits of Tan sheep. The results showed that the intron 2 of the GH gene and the exon 4 of the GHR gene were digested by restriction en- donuclease at Pvu 11 and Hpa 1I loci, respectively, each of them generated two genotypes including BB （0. 375 O）, AB （0. 625 0 ） and DD （ 0. 825 0）, CD （0. 175 0）, respectively. There were significant differences （ P 〈 0.05 ） on the individual birth weight and six - mouth weight of the different genotypes of the GH gene at Pvu II locus, and the difference between the individual birth weight and the weaning weight were highly significant （ P 〈 0.01 ）, and AB was the superior genotype; the birth weight and six - mouth weight of CD genotype of the GHR gene at Hpa H locus were significantly higher （ P 〈 0.05 ） than those of DD genotype, but the two genotypes were no significant different on weaning weight. The gene interaction analysis of the two single nucleotide polymorphisms （SNPs） loci showed that the individual growth traits of the double heterozygous genotype were significantly higher than （P 〈 0.05 ） those of the other kinds of genotype combinations, and the combination effects of multi - marker loci were higher than those of single - marker loci. The results indicate that ABCD is the best genotype combination affecting the growth traits of Tan sheep. Thus, it can be used as a genetic marker for the growth traits in Tan sheep.