title: Coat colour phenotype of Qingyu pig is associated with polymorphisms of melanocortin receptor 1 gene.
abstract: OBJECTIVE
  Qingyu pig, a Chinese indigenous pig breed, exhibits two types of coat colour phenotypes, including pure black and white with black spotting respectively. Melanocortin receptor 1 (MC1R) and agouti signaling protein (ASIP) are two widely reported pivotal genes that significantly affect the regulation of coat colour. The objectives of this study were to investigate whether the polymorphisms of these two genes are associated with coat colour and analyze the molecular mechanism of the coat colour separation in Qingyu pig.
  
  
  METHODS
  We studied the phenotype segregation and used polymerase chain reaction amplification and Sanger sequencing to investigate the polymorphism ofMC1RandASIPin 121 Qingyu pigs, consisting of 115 black and 6 white with black spotted pigs.
  
  
  RESULTS
  Coat colour of Qingyu pig is associated with the polymorphisms ofMC1Rbut notASIP. We only found 2 haplotypes,EQYandEqy, based on the 13 observed mutations fromMC1Rgene. Among which,Eqypresented a recessive inheritance mode in black spotted Qingyu pigs. Further analysis revealed ag.462-463CCinsertion that caused a frameshift mutation and a premature stop codon, thus changed the first transmembrane domain completely and lost the remaining six transmembrane domains. Altogether, our results strongly support that the variety of Qingyu pig's coat colour is related toMC1R.
  
  
  CONCLUSIONS
  Our findings indicated that black coat colour in Qingyu pig was dominant to white with black spotted phenotype andMC1Rgene polymorphism was associated with coat colour separation in Qingyu pig.
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Wu
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Tan
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Linyuan
authors.initials: L
authors.lastname: Shen
authors.affiliation: Department of Animal Husbandry and Veterinary Medicine, Chengdu Agricultural College, Chengdu 611130, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Yang
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Pasturage Station of Tongjiang Agriculture Bbureau, Tongjiang, 636718, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Liao
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Bai
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Surong
authors.initials: S
authors.lastname: Shuai
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Mingzhou
authors.initials: M
authors.lastname: Li
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Xuewei
authors.initials: X
authors.lastname: Li
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Shunhua
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
keywords: Agouti Signaling Protein (ASIP); Coat Colour; Melanocortin Receptor 1 (MC1R); Polymorphism; Qingyu Pig