Investigating the impact of a novel GHRHR gene variant on growth traits in Damascus goats

Abstract

This study investigates the genotype and allele frequencies of three novel SNP loci (c.4218 T>G, c.2203 T>C, and c.7966 A>C) in the GHRHR gene within the Damascus goat breed and their associations with growth traits. The genotype frequencies for c.4218 T>G were 0.65 (TT), 0.15 (TG), and 0.20 (GG), with allele frequencies of 0.73 (T) and 0.27 (G), showing a significant deviation from Hardy-Weinberg equilibrium (HWE). The c.2203 T>C locus had genotype frequencies of 0.75 (TT) and 0.25 (CC), and the c.7966 A>C locus had 0.81 (AA) and 0.19 (CC), both consistent with HWE. Association analysis revealed significant correlations between the c.4218 T>G SNP and body weight and rump width, with the TT genotype showing the highest averages for both traits. The c.2203 T>C SNP was significantly associated with body weight and chest width, with the TT genotype again showing higher averages. The c.7966 A>C SNP was associated with chest depth and body length, with the AA genotype displaying lower averages for these traits. In silico predictions using multiple computational tools indicated that the identified missense SNP (p.31Ile>Ser) is novel and likely deleterious to the GHRHR protein's function and stability. Molecular docking demonstrated that the wild-type GHRHR binds more effectively with G protein alpha compared to the mutated form, predicting a mechanism through which this variant reduces the interactions of GHRHR with its cognate proteins. These findings provide valuable insights into the genetic factors influencing growth traits in Damascus goats and highlight the potential impact of the p.31Ile>Ser SNP on GHRHR functionality. This research underscores the importance of incorporating genetic markers in breeding programs to enhance growth traits and overall productivity.