Research article

Polymorphisms of the IGF1R Gene and Their Genetic Effects on Chicken Early Growth and Carcass Traits

Mingming Lei , Xia Peng , Min Zhou , Chenglong Luo , Qinghua Nie and Xiquan Zhang

BMC Genetics 2008, 9:70doi:10.1186/1471-2156-9-70

Published:	7 November 2008

Abstract (provisional)

Background

The insulin-like growth factor I receptor (IGF1R) has an important effect on growth, carcass, and meat quality traits in many chicken species. However, few studies on associations of the IGF1R gene with growth and carcass traits were reported in chickens. The objectives of the present study were to study the associations of the IGF1R gene with chicken early growth and carcass traits using a neutral test, variation scan of the gene, genetic diversity observation, linkage disequilibrium analyses and association analyses. Result The tree of the amino acid sequence for 15 species showed that the IGF1R gene was conservative in the whole evolution of the mammalian animals and chickens. In the length of 10,818 bp, 70 single nucleotide polymorphisms were identified in the IGF1R gene. The allelic and genotypic frequency distribution, genetic diversity and linkage disequilibrium of 18 single nucleotide polymorphisms (SNP) in the Xinghua and White Recessive Rock chickens showed that the 6 of them were possibly associated with growth traits. Association analyses showed that the A17299834G SNP was significantly associated with chicken carcass body weight, eviscerated weight with giblets, eviscerated weight, body weight at day 28, 35, 56, leg length at day 56, and gained body weight during 0-4 weeks. The haplotypes of the A17307750G and A17307494G were associated with early growth traits. The haplotypes of the A17299834G and C17293932T were significantly associated with most of the early growth traits and carcass traits.

Conclusion

There were rich polymorphisms in the chicken IGF1R gene. Several SNPs associated with chicken early growth traits and carcass traits were identified in the IGF1R gene by genetic diversity, linkage disequilibrium, and association analyses in the present study.