Nie Changsheng, Qu Liang, Li Xinghua, Jiang Zhihua, Wang Kehua, Li Haiying, Wang Huie, Qu Changqing, Qu Lujiang, Ning Zhonghua
State Key Laboratory of Animal Nutrition, Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China.
Jiangsu Institute of Poultry Science, Chinese Academy of Agricultural Sciences, Yangzhou, China.
Front Genet. 2021 Apr 30;12:566047. doi: 10.3389/fgene.2021.566047. eCollection 2021.
Although the genetic foundation of chicken body feather color has been extensively explored, that of tail feather color remains poorly understood. In the present study, we used a synthetic chicken dwarf line (DW), derived from hybrids bred between a black tail chicken breed, Rhode Island Red (RIR), and a white tail breed, dwarf layer (DL), to investigate the genetic rules associated white/black tail color. Even though the body feathers are predominantly red, the DW line still comprises individuals with black or white tails after more than 10 generations of self-crossing and selection for the body feather color. We first performed four crosses using the DW chickens, including black-tailed males to females, reciprocal crosses between the black and white, and white males to females to elucidate the inheritance pattern of the white/black tail. We also performed a genome-wide association (GWA) analysis to determine the candidate genomic regions underlying the tail feather color using black tail chickens from the RIR and DW lines and white individuals from the DW line. In the crossing experiment, we found that (i) the white/black tail feather color is independent of body feather color; (ii) the phenotype is a simple autosomal trait; and (iii) the white is dominant to the black in the DW line. The GWA results showed that seven single-nucleotide polymorphisms (SNPs) on chromosome 24 were significantly correlated with tail feather color. The significant region (3.97-4.26 Mb) comprises nine known genes (, , , , , , , , and ) and five anonymous genes. This study revealed that the white/black tail feather trait is autosome-linked in DW chickens. Fourteen genes were found in the significant ~0.29 Mb genomic region, and some, especially , are suggested to play critical roles in the determination of white/black tail feather color. Our research is the first study on the genetics underlying tail feather color and could help further the understanding of feather pigmentation in chickens.
尽管鸡体羽颜色的遗传基础已得到广泛研究，但尾羽颜色的遗传基础仍知之甚少。在本研究中，我们使用了一个合成鸡矮小型品系（DW），该品系源自黑尾鸡品种罗德岛红鸡（RIR）和白尾品种矮小型蛋鸡（DL）杂交培育的杂种，以研究与白/黑尾羽颜色相关的遗传规律。尽管体羽主要为红色，但经过10多代的自交和体羽颜色选择后，DW品系中仍包含黑尾或白尾个体。我们首先使用DW鸡进行了四次杂交，包括黑尾雄鸡与雌鸡杂交、黑鸡与白鸡的正反交以及白尾雄鸡与雌鸡杂交，以阐明白/黑尾羽的遗传模式。我们还进行了全基因组关联（GWA）分析，以确定使用RIR和DW品系的黑尾鸡以及DW品系的白鸡个体尾羽颜色潜在的候选基因组区域。在杂交实验中，我们发现：（i）白/黑尾羽颜色与体羽颜色无关；（ii）该表型是一个简单的常染色体性状；（iii）在DW品系中白色对黑色为显性。GWA结果表明，24号染色体上的7个单核苷酸多态性（SNP）与尾羽颜色显著相关。显著区域（3.97 - 4.26 Mb）包含9个已知基因（、、、、、、、、和）和5个未知基因。本研究表明，白/黑尾羽性状在DW鸡中是常染色体连锁的。在约0.29 Mb的显著基因组区域中发现了14个基因，其中一些基因，尤其是，被认为在白/黑尾羽颜色的决定中起关键作用。我们的研究是关于尾羽颜色遗传基础的首次研究，有助于进一步了解鸡的羽毛色素沉着。
