A novel heterozygote allele in caprine melanocortin 1 receptor (MC1R) gene: an association with heat stress traits

Climate change negatively influences the productive and reproductive abilities of goats. There is a need to understand the relationship between heat stress and genes that may aid in the development of climate-resilient goats. Melanism variation in goats plays a role in thermoregulation, in which the melanogenic genes have a pleiotropic effect on the regulation of physiological responses and behavior that are altered due to heat stress in the animals. Thus, the present study was conducted to establish a possible association between the coat color gene (MC1R) and heat stress characteristics. The physiological responses and cortisol levels were recorded in forty different coat-colored goats. The genotyping of the animals revealed four SNPs at the 183 rd (C/T), 332 nd (C/G), 748 th (G/T), and 801 st (C/G) positions, among which the black and brown goat populations had novel SNPs at the 332 nd position. Eight haplotypes were constructed, and an association study revealed that haplotypes (CCGG, TCGG, and CCTC) that were linked to white animals had lower cortisol values, rectal temperature, skin temperature, and respiration rate. The multivariate and cluster analyses revealed that the white goats were distinct from the rest of the goats. In addition, the docking results revealed the residues that were forming the interaction complex, which could play a role in melanogenesis in the animals and, in turn, the heat stress ability of the goats. Altogether, the results of the present study could pave the way for more research into coat color genes and their relationship with heat stress traits.