Study On The Relationship Between Polymorphism Of MC4R, POU1F1 Gene And Growth & Carcass Characteristics Of Jinghai Yellow Chicken

Melanocortin-4 receptor(MC4R) is a kind of peptide secreted by animal ventral hypothalamus nuclear,involved in inhibiting the increase in body weight.Pituitary specific transcription factor 1(POU1F1) regulated the growth and development of body cell,fasted the gene expression such as GH,PRL,TSH-β.In order to give the effective molecular markers for the marker-assisted selection(MAS) on early production performance of chickens,SNPs polymorphism of MC4R and POU1F1 gene were conducted on Jinghai Yellow chicken breed by PCR-SSCP and DNA sequencing method. The relationship between SNPs polymorphism and growth performance,carcass characteristics had also been analyzed by GLM model.The differential expression level were detected about POU1F1 and relative gene in pituitary,and MC4R gene in adrenal gland,and compared between Jinghai Yellow chicken and Youxima chicken.The results were as follows:(1)Three genotypes of AA,AB,AB with primer P1 of MC4R gene were detected,the allele frequency of A,B were 0.929 and 0.071 respectively.With primer P2,results showed three genotypes of CC,CD,DD,and the allele frequency of C and D allele was 0.72 and 0.28 respectively.The gene frequencies and genotype frequencies both reached the Hardy-Weinberg equilibrium at those two loci indicated by the x~2 test.Through sequencing alignment,results showed that there was a G→C on the site of 662bp with primer P1 of MC4R gene,and a insertion of C base between the site of 733 and 734bp. These two polymorphism sites were both detected first in MC4R gene of chicken.(2)Three genotypes of AA,AB,AB with primer P1of POU1F1 gene were detected, the allele frequency of A,B were 0.925 and 0.075 respectively.With primer P6,showed three genotypes of AA,AB,AB,and the allele frequency of A and B allele was 0.5 and 0.5 respectively.With primer P11,showed three genotypes of AA,AB,AB,and the allele frequency of A and B allele was 0.396 and 0.604 respectively.The gene frequencies and genotype frequencies both reached the Hardy-Weinberg equilibrium at P6,P11 loci indicated by the x~2 test,but P1 loci not reached.Through sequencing alignment,results showed that there was a G→C on the site of 1876 bp,and a C→T on the site of 1882 bp with primer P1 of POU1F1 gene,and a A→T on the site of 3684 bp with primer P6,a T→C on the site of 4573 bp with primer P11.(3)The body weight,body measure and carcass trait of AB genotype individual of P1 primer in MC4R gene were better than other genotype,DD genotype individual was the same.The body weight and measure of the combined genotype AA/DD individual were better than other combination.That was the same such as AA genotype of P1,AA genotype of P6,AB genotype of P11 in POU1F1 gene.So,Those SNPs of MC4R and POU1F1 gene had important effect on the growth performance and carcass characteristics in Jinghai Yellow chicken breed,and could be used to MAS as molecular markers of correlation characteristics.(4)The correlation between body measure trait and carcass were analyzed.The results showed that there was a significant or very significant correlation between the traits of advantage genotype.But there was not significant correlation between the muscle stomach and other traits.(5)The expression level of POU1F1,GH,PRL gene in pituitary of Jinghai Yellow chicken had significantly higher than it in Youxima Chicken.The expression level of MC4R gene in adrenal gland of Jinghai Yellow male chicken had significantly higher than it in Youxima male Chicken,but it was not significant both in female and total.Both in Jinghai Yellow chicken and Youxima chicken,the expression level had a positive correlation between POU1F1 gene and GH,PRL gene.(6)In Jinghai Yellow chicken,the expression level of MC4R gene had a greatly significant correlation with liver weight;but in Youxima chicken,the expression level of MC4R gene had a greatly significant correlation with liver weight and heart weight.