绵羊Izumo1基因多态性及其与产羔数关联分析

为研究Izumo1基因多态性及与产羔数关系,本研究利用PCR和直接测序法对小尾寒羊和苏尼特羊的Izumo1基因DNA序列进行扩增、测序和BLAST分析,并和本课题组前期绵羊重测序数据进行比对,筛选出Izumo1基因SNP位点。同时,采用Sequenom MassARRAY~?技术进行基因分型,并对其SNP位点的基因型和等位基因频率在各群体中的分布进行研究。结果表明:小尾寒羊Izumo1基因DNA全长序列3 385 bp,苏尼特羊Izumo1基因DNA全长序列3 382 bp;筛选出8个Izumo1基因SNP位点,经过初步筛选,将在小尾寒羊、苏尼特羊、滩羊、萨福克羊、杜泊羊、草原藏羊这6个绵羊品种中位点分布没有差异的SNP位点排除,最终筛选获得的g.54412135AG和g.54412107CA 2个位点。Izumo1基因g.54412135AG位点在多羔和单羔绵羊品种中存在GG、GA和AA 3种基因型,G基因为优势等位基因;g.54412107CA在多羔品种中存在CC和CA 2种基因型,而在单羔品种中存在CC、CA和AA 3种基因型,C基因为优势等位基因,其基因型频率和基因频率在单、多羔绵羊群体间的分布差异均极显著(P0.01);群体遗传学分析得出g.54412135AG多态位点在6个品种中的多态信息含量(PIC)都属于低度多态(PIC0.25);g.54412107CA多态位点在杜泊羊中属于中度多态(0.25PIC0.5),在其他5个品种中都属于低度多态(PIC0.25),然而,关联分析发现Izumo1基因g.54412135AG和g.54412107CA位点的不同基因型与小尾寒羊不同胎次产羔数之间不存在显著关联(P0.05)。

Polymorphism of Izumo1 gene and its association with litter size in sheep(Ovis aries)

This study aimed to investigate the polymorphism of Izumo1 gene and its association with litter size in sheep. The DNA sequences of Izumo1 gene in Small Tail Han sheep and Sunite sheep were amplified and sequenced using PCR and direct sequencing, and then analyzed by BLAST. SNPs of Izumo1 gene were screened out by comparing with the previous re-sequencing data of sheep in the laboratory. Sequenom MassARRAY^® was used to genotype and the distribution of genotype and allele frequencies of the SNP loci in each group was studied. The results showed: The full lengths DNA sequence of Izumo1 gene were 3 385 bp in Small Tail Han sheep and 3 382 bp in Sunite sheep. Eight SNP loci of Izumo1 gene were screened out. After preliminary screening, the SNP loci with no difference to those of Small Tail Han sheep, Sunite sheep, Tan sheep, Suffolk sheep, Dorper sheep and Prairie Tibetan sheep were excluded. Two loci, g. 54412135A>G and g. 54412107C>A were finally selected. Polymorphism analysis showed that: There were three genotypes of GG, GA and AA in g. 54412135A>G locus of Izumo1 gene in monotocous and polytocous breeds, and G gene was the dominant allele; There were CC and CA genotypes in g. 54412107C>A polytocous breeds, and CC, CA and AA genotypes in monotocous breeds. C gene was the dominant allele, the genotype frequency and allele frequency of this locus were significantly different among high fecundity and low fecundity sheep breeds(P<0. 01). Population genetic analysis showed that: The polymorphism information content(PIC)of g. 54412135A>G polymorphism loci in six breeds belonged to low polymorphism(PIC<0. 25). The g. 54412107C>A polymorphism locus belonged to moderate polymorphism(0. 25Izumo1 gene g. 54412135A>G and the g. 54412107C>A loci and litter size from different parity of Small Tail Han sheep(P>0. 05)by the association analysis.