Sequence characterization and genetic variability analysis of GHR, IGF1, and IGFBP-3 genes in nine Indian goat breeds

The genes that are part of the somatotropic axis play a crucial role in the regulation of growth and development of goat and other livestock animals. The identification of genetic polymorphisms in these genes will enable us to evaluate the biological relevance of such polymorphisms and to gain a better understanding of quantitative traits like growth. The present study was undertaken with the objective to analyze the caprine growth hormone receptor (GHR), insulin-like growth factor 1 (IGF1), and insulin-like growth factor binding protein 3 (IGFBP-3) genes to gain insight into the polymorphisms in these genes across different indigenous goat breeds in a panel of 80 animals. The comparative gene sequence analysis in all Capra hircus breeds under study revealed 31 single nucleotide polymorphisms (SNPs) across different loci of GHR, IGF1, and IGFBP-3 genes. Out of 31 SNPs detected, 18, 8, and 5 SNPs were present in IGF-1, IGFBP-3, and GHR genes, respectively. All the mutations pointed out in the GHR and IGF1 genes were found to be synonymous and 6 of 8 SNPs in IGFBP-3 were found to be nonsynonymous. All the detected mutations were reported here for the first time. The frequencies of the SNPs were assessed in nine different goat breeds. Across breeds, the average frequency of the least frequent alleles ranged from 0.02 to 0.17.