Study on the Polymorphisms of IGF-ⅠR Gene Alu Ⅰ Locus and Genetic Effect on Growth and Reproduction Traits in Bian Chicken

Single nucleotide polymorphisms (SNPs) in exon 2 of insulin-like growth factor Ⅰ receptor (IGF-ⅠR) gene were detected by PCR-RFLP in Bian chicken,which was to find the correlation markers of growth and reproduction traits in Bian chicken.The results showed that AluⅠsite displayed polymorphic, and a G→A mutation at the position of the 376 bp in exon 2 was occurred. There were three genotypes (GG, GA and AA), the genotypes frequencies were 0.687, 0.296 and 0.017, respectively, GG genotype was the dominant genotype, the frequency of G allele was 0.835, which was the dominant allele. This site was in Hardy-Weinberg equilibrium (P>0.05).Correlation analysis showed that GG genotype had significantly higher body weight than those of GA genotype at the age of 8, 14, 16 and 18 weeks (P<0.05);The GG geno type had extremely significantly higher body weight at first egg than those of GA genotype (P<0.01),but it didn't mean that this locus could be used as a genetic marker for reproduction traits in Bian chicken. This results suggested that the AluⅠsite (G→A) in exon 2 of IGF-ⅠR gene could be used as a genetic marker for growth traits in Bian chicken.