绵羊线粒体基因变异与产羔数性状的关联分析

Association Analyses between Mitochondrial Coding Gene Variations and Sheep Litter Size

本研究旨在分析mtDNA变异与产羔数性状的关系。以杜泊、陶赛特、萨福克绵羊为研究对象,通过线粒体基因组测序、基因型分析等技术发现,杜泊羊线粒体基因组编码区存在25个突变位点,包括rRNA突变位点2个,tRNA突变位点2个,多肽编码基因突变位点21个(包括错义突变9个和同义突变12个);陶赛特羊线粒体基因组编码区存在20个突变位点,包括rRNA突变位点5个,tRNA突变位点1个,多肽编码基因突变位点14个(包括错义突变3个和同义突变11个);萨福克羊线粒体基因组编码区存在77个突变位点,包括rRNA突变位点7个,tRNA突变位点3个,多肽编码基因突变位点67个(包括错义突变7个和同义突变60个)。杜泊、陶赛特绵羊mtDNA各突变位点均与产羔数关联不显著;萨福克绵羊中发现的14个变异位点与产羔数显著相关(P<0.05),其中单个突变位点(T7759C)和单倍型(ATTCATTAAACTTT)最大效应均为0.22只·胎-1。结果表明,杜泊、陶赛特绵羊产羔数性状线粒体基因效应不显著;萨福克绵羊mtDNA变异与产羔数显著相关。

The aim of the present study was to explore the effects of mtDNA on litter size in sheep.Genome sequencing and genotyping technologies were used for DNA variation analyses on mitochondrial coding genes in Dorper,Dorset and Suffolk sheep.In Dorper sheep,twenty-five mtDNA variations were detected,including 2mutations in rRNA and tRNA genes,respectively,and 21 variations in polypeptide-coding genes（including 9missense mutations and 12 synonymous mutations）.For Dorset sheep,totally 20 variations,including 5mutations in rRNA genes,1mutation in tRNA genes,and 14 substitutions in polypeptide-coding genes（including 3missense mutations and 11 synonymous mutations）were detected.In Suffolk sheep,there were 77 mutations in mtDNA coding genes,including 7and 3substitutions in rRNA and tRNA genes,and 67 mutations in polypeptide-coding genes which contained 7missense mutations and 60 synonymous mutations.The mtDNA mutations presented poor associations with litter size in Dorper and Dorset sheep.However,in Suffolk sheep,14 mtDNA mutations were significantly associated with litter size（P〈0.05）,which both of the maximal values for the effects of the single mutation（T7759C）and hap-lotype（ATTCATTAAACTTT）were 0.22 per parity.The mtDNA had poor effects on litter size in Dorper and Dorset sheep.Mitochondrial DNA variations were significantly associated with litter size in Suffolk sheep.