Association of insulin receptor substrate 1 ( IRS-1 ) gene polymorphism with growth and litter-related traits in NMER rabbits.

This study investigated the associations between the c.189G > T polymorphism of the insulin receptor substrate-1 ( IRS-1) gene and the growth and litter size-related traits in the Native rabbit in Middle Egypt (NMER). One hundred sixty-two NMER rabbits were genotyped by RFLP-PCR using Sau3AI restriction enzyme and the associations of the reported genotypes with body weights at 5 th , 6 th , 8 th , 10 th , and 12 th week old, body gain, and daily gain plus, the litter size-related traits were determined. Additionally, the genotypic and allelic frequencies, the effective ( N e ) and observed ( N A ) numbers of alleles, observed ( H o ) and expected ( H e ) heterozygosity, Hardy-Weinberg equilibrium (HWE), and the decrease in heterozygosity because of inbreeding ( F IS ) were calculated. Three genotypes; GG, GT, and TT with 0.65, 0.33, and 0.02 frequencies, respectively which fit HWE were reported. These genotypes displayed a marked low F IS value. Significant associations of the genotypes with the body weights, and gains, except at the 5 th week old determined with superiority of the GT genotype compared with the other genotypes. All reported litter size-related traits significantly varied among different genotypes. In summary, the c.189G > T SNP of the IRS-1 gene is an effective genetic marker to improve growth performance and litter size traits of the NMER rabbits.