Identification of SNPs in growth-related genes in Colombian creole cattle.

Colombian creole cattle have important adaptation traits related to heat tolerance and reproductive and productive efficiency. Romosinuano (ROMO) and Blanco Orejinegro (BON) are the most common breeds used by Colombian cattle breeders. Growth traits are of prime importance in these animals, which are mainly raised for beef production. Genes encoding growth hormone, growth hormone receptor, homeobox protein, insulin growth factor binding protein 3, leptin, and myostatin have been associated with physiological growth pathways in cattle and other species. We therefore aimed to identify single nucleotide polymorphisms (SNPs) within these genes in ROMO, BON, and Zebu cattle. DNA regions of these genes were sequenced in 386 animals; 47 new SNPs were found, of which 14 were located in the exonic regions, thereby changing the protein sequence. An association of SNPs with weaning weight (WW), daily weight gain at weaning (DWG), and weight at 16 months (W16M) traits was deduced. The genetic analysis revealed several SNPs related to these traits. The SNP GhRE06.2 had a significant association with WW and the SNP Lep03.4 was highly associated with DWG and W16M. Other polymorphisms were significantly associated with WW and DWG, although they did not surpass the Bonferroni significance threshold. The new mutations identified may indicate important points of genetic control in the DNA that could be responsible for changes in the expression of the analyzed traits. These SNPs might be used in future breeding programs to improve the productive performance of cattle in beef farms.