滩羊毛色的全基因组关联分析

Genome-wide association studies for coat color in Tan sheep

滩羊不仅肉质鲜美,其所产的二毛裘皮在国内外也享有盛誉,毛色是滩羊重要的经济性状。为检测影响滩羊毛色的基因组区域,利用美国Affymetrix绵羊600K基因分型芯片对宁夏盐池地区具有代表性毛色的96只滩羊个体(全白、白毛黑头、白毛褐或黄头)进行基因分型,并采用Logistic回归方法进行全基因组关联分析。通过Bonferroni校正,检测到5个与毛色显著关联的SNPs。这些SNPs分别位于或邻近2个已知基因(MC1R和TCF 25)。其中MC1R基因参与调控黑色素的合成,研究表明其与绵羊毛色相关。而TCF 25基因与MC1R基因距离很近,可能由于存在一定程度的连锁不平衡而被鉴定到。本研究进一步解析了滩羊毛色性状的遗传机理,为滩羊毛色性状的标记辅助选育提供科学依据。

Tan sheep,not only famous for its delicious meat,but also enjoys high reputation at home and abroad for its one-month lamb s fur.Therefore,the coat color is an important economic trait of Tan sheep.To detect the genomic regions which affecting the coat color of Tan sheep,the genome-wide association studies(GWAS)were performed based on Logistic regression method using genotypes from the America Affymetrix 600K genotyping chips for this trait.Genotyping was performed on 96 representative tan sheep of Yanchi,Ningxia,which had pure white bodies,white bodies with black heads and white bodies with brown or yellow heads.By Bonferroni correction,we have found five SNPs significantly associated with coat color,which were located within or close to 2 known genes(MC1R and TCF25).The MC1R is involved in the regulation of melanin synthesis that has been shown to be related to the color of sheep by numerous studies.The TCF25 is located nearby MC1R,so the identification of TCF25 maybe a result of linkage disequilibrium between these two genes.Our studies explained the genetic mechanism of coat color of Tan sheep,and provided scientific basis for assisted breeding by mark the color traits of Tan sheep.