GPX2 Gene Affects Feed Efficiency of Pigs by Inhibiting Fat Deposition and Promoting Muscle Development

SIMPLE SUMMARY: Glutathione peroxidase 2 (GPX2) gene expression differs between individuals with different GPX2 polymorphism. Individuals with high GPX2 expression had thinning 100 kg backfat (BF) thickness, no change on average daily gain (AG) and lower feed conversion ratio (FCR) and residual feed intake (RFI) in Duroc pigs. The reason for this result could be that increasing GPX2 could inhibit the adipocyte proliferation and differentiation, promoting the lipid degradation. Meanwhile, GPX2 may promote muscle cells’ proliferation and myogenic differentiation. Overall, our fundings indicate that GPX2 can transfer more nutrients to less fat deposition direction, providing the material basis for animal weight gain. ABSTRACT: GPX2 has been recognized as a potential candidate gene for feed efficiency in pigs. This article aimed to elucidate polymorphism of GPX2 associated with feed efficiency and its related molecular mechanism. In this study, seven single nucleotide polymorphisms (SNP) of GPX2 were found among 383 Duroc pigs. In addition, seven SNPs and ALGA0043483 (PorcineSNP60 BeadChip data in 600 Duroc pigs), which are near the GPX2 gene, were identified in one haplotypes block. Furthermore, associated studies showed that the genotype of GPX2 has significant association with weaning weight and 100 kg BF in Duroc pigs. In addition, the AG had no effect when the backfat became thinner, and the FCR and RFI traits had a tendency to decrease in the G3 + TT combination genotype, accompanied by an increase of GPX2 expression in backfat and muscle tissues. At the cellular level, the adipocyte proliferation and ability of adipogenic differentiation were reduced, and the lipid degradation increased in 3T3-L1 when there was overexpression of GPX2. In contrast, overexpression of the GPX2 gene can promote the muscle cell proliferation and myogenic differentiation in C2C12 cells. In other words, GPX2 has the effect of reducing fat deposition and promoting muscle development, and it is a candidate gene for backfat and feed efficiency.