The impact of Genetic Polymorphism of THRSP Gene on Body Dimensions and Growth Traits in Local and Shami Goats

Abstract

This study was conducted at the Ruminant Research Station of the Agricultural Research Department, Ministry of Agriculture, located west of Baghdad in the Akerkouf region, from October 1, 2023, to April 1, 2024. It aimed to investigate the genetic polymorphism of the THRSP gene through detecting SNPs in a specific gene fragment and studying its association with body measurements (chest circumference, body length, height at withers  and height at rump) and growth traits (birth weight, weaning weight, weight gain from birth to weaning, and current weight) in local and Shami goats. Sequencing of the targeted gene fragment revealed a size of 486 bp in both goat breeds, with a single nucleotide change at position 322 within exon 1, changing from G to C. This missense mutation produced three genotypes: GG, GC, and CC. In local goats, the highest frequency was for GG, followed by CC, then GC. Similarly, in Shami goats, GG was most frequent, followed by GC, then CC. These differences were statistically significant (P≤0.01). In local goats, the GC genotype outperformed the other two genotypes in weaning weight and weight gain, while the genotypes of the gene had no significant effect on the other studied traits. In Shami goats, no significant differences were observed between the three genotypes regarding growth traits and body dimensions. Genotype GG outperformed the others in observed and expected numbers. Biodiversity indices showed that the effective allele number was lower than the actual allele count, and the Shannon-Weaver index values were low in both breeds.