Single Nucleotide Polymorphism Of MC4R Gene Associated With Growth Traits In Jinghai Yellow Chicken

Melan-cortexin receptor 4 (MC4R), a polypeptide, is one of the five melan-cortexin family numbers, secreted by ventromedial hypothalamic nucleus (VMH). MC4R, as a transmembrane neurorerecepor, pertaining to G-protein-coupled receptor (GPCRS) superfamily.α-Melanocyte stimulating hormone (α-MSH) is the natural endogenetic receptor of MC4R, they refrain from Body weight increasing when matched. MC4R mediates Leptin protein in mammal, it is a significant signal molecule in regulating energy balance and energy dynamic balance, especially in controlling appetite, Body weight, energy metabolism. This study was to detect the polymorphisms of MC4R genes in Jinghai yellow chickens by DNA sequencing and PCR-SSCP methods. The SNPs were detected with population genetic methods. Meanwhile, the correlation between gene polymorphic sites and the growth traits were investigated.The main results were as follows:1 Three genotypes were found in PCR product by two primers of MC4R gene. The distributions of three genotypes were not in Hardy-Weinberg Equilibrium statuses. It maybe related to long-term selection and breeding.2 The automated sequencing using PCR-SSCP technology indicated that single nucleotide loci mutations were G→C at 662bp position in exon for mutant primer P1 and a C insertion at 733-734bp site in exon for mutant primer P2.3 The statistical analysis of the correlation between all genotypes in exon of MC4R with growth traits in Jinghai Yellow chicken showed that B allele with negative correlation to body weight at every week.4 The statistical analysis of the correlation between all genotypes in exon for primer P1 of MC4R with slaughter and body-ruler traits in Jinghai Yellow chicken validated that AB type with positive correlation to organ and body-ruler.5 The statistical analysis of the correlation between all genotypes in exon for primer P2 of MC4R with growth traits in Jinghai Yellow chicken accounted for the C insertion with positive correlation to body weight at every week.6 The statistical analysis of the correlation between all genotypes in exon for primer P2 of MC4R with slaughter and body-ruler traits in Jinghai Yellow chicken showed that C insertion with positive correlation to slaughter and body-ruler traits in record.7 The statistical analysis of the correlation between different genotype combinations, determined by primers P1 and P2 for MC4R gene, and growth traits in Jinghai Yellow chicken illuminated that AA/DD type was the best.Aggregate analysis resulted that polymorphic sites in PCR product by two primers of MC4R gene had important influence on growth traits and productive performances according to this study, might be used as molecular makers for growth traits of chicken in selection.