探究MC1R基因在江西地方鸡中的变异、单倍型及其对羽色的影响

The Variation and Haplotype of MC1R Gene and Its Effect on the Plumage Coloration of Indigenous Chicken Breeds in jiangxi Province,China

【目的】羽色不仅是家鸡的重要外观特征,因其影响优质活禽上市时消费者的选择,进而还具有重要的经济意义。本研究旨在探究黑素皮质激素受体1(MC1R)基因在江西地方鸡种中的变异及其对羽色的影响。【方法】采用PCR产物直接测序法,对MC1R基因在333个源自东乡绿壳蛋鸡、余干乌骨鸡、南城黑鸡、安义瓦灰鸡、白耳黄鸡、宁都黄鸡、康乐黄鸡、丝羽乌骨鸡、崇仁麻鸡和修水黄羽乌鸡的个体的变异位点进行鉴别,随后利用PHASE软件构建上述变异位点在各鸡群体中的单倍型并分析其与羽色的关系。【结果】共检测到MC1R基因变异位点15个,包括10个错义突变位点、4个同义突变位点和1个缺失突变位点,其中c.366C>G(p.122Ile>Met)和c.547_549delAAC(p.183delAsn)为新发现的变异位点;共检测到31种单倍型(H0-H30),其中6种为新单倍型(H11、H14、H15、H16、H17和H27)并只出现于黄羽和白羽个体中。黑羽个体(东乡绿壳蛋鸡、余干乌骨鸡和南城黑鸡)均含有单倍型H4或H2,二者共同含有c.212T>C(p.71Met>Thr)和c.274G>A(p.92Glu>Lys)位点,其中东乡绿壳蛋鸡仅具有H4一种单倍型。灰羽个体(安义瓦灰鸡)均携带H4或H5单倍型且H5比前者多含有c.636G>A和c.637T>C(p.213Cys>Arg)2个变异位点。此外,单倍型H7比H4多含有c.644A>C(p.215His>Pro)位点,其中黑羽个体中未发现有CC突变型。黄羽群体(白耳黄鸡、宁都黄鸡、康乐黄鸡和修水黄羽乌鸡)的优势单倍型主要为H24和H25。白羽群体(丝羽乌骨鸡)的优势单倍型为H7和H15。【结论】MC1R基因在江西地方鸡种中变异丰富,c.212T>C(p.71Met>Thr)、c.274G>A(p.92Glu>Lys)和c.644A>C(p.215His>Pro)位点与江西地方鸡黑羽形成相关,可将其作为中国地方鸡黑羽性状选育的特异性分子标记;H5单倍型的c.637T>C(p.213Cys>Arg)位点可能与安义瓦灰鸡“灰羽”的形成有关。

[Objective]Plumage color is not only an important appearance feature of chicken breeds,but also is of important economic significance because it affects the choice of consumers when quality poultry are put on the market.Jiangxi Province is rich in local chicken resources with unique characteristics,among which feather color is prominent.The purpose of this study was to investigate the variation of MC1R gene in Jiangxi local chicken breeds and its effect on feather color.[Method]The variation in MC1R gene was identified in 333 samples from Dongxiang blue-shell egg layer,Yugan black bone chicken,Nancheng black chicken,Anyi grey chicken,white ear yellow chicken,Ningdu yellow chicken,Kangle yellow chicken,silky feather black-bone chicken,Chongren partridge chicken and Xiushui yellow feather black-bone chicken via a PCR products resequencing method.Then,based on the above mutations the haplotypes were constructed for each animal by a PHASE software and their effects on plumage color were evaluated.[Result]A total of fifteen mutations were detected in the MC1R gene,including 10 missense mutations,4 synonymous mutations and 1 deletion mutations.Among them,both c.366C>G(p.122Ile>Met)and c.547_549delAAC(p.183delAsn)were newly discovered mutation loci,and 31 haplotypes(H0-H30)were constructed,among which 6 new haplotypes(H11,H14,H15,H16,H17 and H27)appeared only in yellow or white feather populations.The haplotype H4 or H2 was found in all black feathered individuals(Dongxiang green shell layer,Yugan black bone chicken and Nancheng black chicken).Both of them contained c.212T>C(p.71Met>Thr)and c.274G>A(p.92Glu>Lys)loci.Dongxiang green shell layer only had H4 haplotype.All the grey feather individuals(Anyi wa-grey chicken)carried H4 or H5 haplotypes,and H5 contained more c.636G>A and c.637T>C(p.213Cys>Arg).In addition,H7 contained more c.644A>C(p.215His>Pro)locus than H4,and CC mutation was not found in all black feather individuals.The dominant haplotypes of yellow feather population(Baier yellow chicken,Ningdu yellow chicken,Kangle yellow chicken and Xiushui yellow feather black-bone chicken)were mainly H24 and H25.In addition,the dominant haplotypes of white feather population(silky silky feather black-bone chicken)were H7 and H15.[Conclusion]MC1R gene had abundant variation in Jiangxi local chicken breeds.Comprehensive variation and haplotype analysis showed that the loci affecting black feather formation of Chinese indigenous chicken were c.212T>C(p.71Met>Thr),c.274G>A(p.92Glu>Lys)and c.644A>C(p.215His>Pro).The above three loci can be used as specific molecular markers for breeding black feather traits in Chinese local chickens.Furthermore,c.637 T>C(p.213Cys>Arg)locus of H5 haplotype may be related to the dilution of feather color of Anyi grey chicken.