“…MC1R is a highly polymorphic gene, and more than 200 variants have been found ( Zanna et al, 2021 ). Some studies have shown that MC1R mutations or base substitutions can affect various phenotypes of feather color in chickens ( Liu et al, 2010 ; Oh et al, 2010 ; Kim and Production 2020 ). When Zhang ( Zhang et al, 2020 ) studied the formation of Yunnan Piao chickens’ tile gray feathers, through sequencing and alignment of the whole coding region of MC1R , a total of 10 SNP sites were detected, of which 8 were nonsynonymous mutations that caused amino acid changes.…”