Additive and Dominance Effects of MC4R and PIT1 Polymorphisms on Production and Carcass Traits in Duroc Pigs

Abstract

This study aimed to estimate the allelic and genotypic frequencies of single nucleotide polymorphisms (SNPs) of MC4R (melanocortin-4-receptor gene) and PIT1 (pituitary specific transcription factor-1) genes, and their additive dominance genetic effects on production and carcass traits in Duroc pigs. A total of 2170 tail tissue samples (1728 gilts and 442 male pigs) were collected from Dabaco Nucleus Breeding Pig Company, Bac Ninh province, Vietnam from January 2017 to June 2020. Polymorphisms in the MC4R and PIT1 genes were detected using the PCR-RFLP method. For MC4R, the frequencies of alleles A and G were 0.430 and 0.570, respectively. For PIT1, the frequencies of alleles A and B were 0.460 and 0.540, respectively. The genotype frequency distribution of the MC4R gene was in Hardy-Weinberg equilibrium (P = 0.375), but the genotype frequency distribution of PIT1 (P <0.001) was not. The MC4R and PIT1 polymorphisms were significantly associated with final body weight and average daily gain (P <0.001). Significant additive effects were also found (P <0.05) for the two traits. The selection of individuals with the MC4R genotype AA and PIT1 genotype AA could improve final body weight and average daily gain in Duroc pigs.

The influence of feeding level on the growth of pigs depending on their genotype

“…Both nongenetic factors, such as pig feeding system (Lebret, 2008;Bankovska et al, 2020) or environmental temperature (Vashchenko & Berezovskyi, 2021) and genetic factors, such as MC4R genotype (Kim et al, 2000;Fan et al, 2009;Loos & Yeo, 2022), influence the intensity of growth and deposition of backfat. Unlike the human melanocortin-4-receptor gene, for which many polymorphic variants have been described, some of which are associated with appetite and obesity (Crovesy & Rosado, 2019;Chiurazzi et al, 2020;Mahmoud et al, 2022), very few polymorphic variants of the MC4R gene have been found in pigs (Fan et al, 2009;Llambí et al, 2020;Bo et al, 2022). A large number of scientists consider p.Asp298Asn to be the most practical melanocortin-4-receptor gene polymorphism (Fan et al, 2009;Gondim et al, 2019;Zhang et al, 2020).…”