Association Analysis of METTL23 Gene Polymorphisms with Reproductive Traits in Kele Pigs

Methyltransferase-like 23 (<i>METTL</i>23) is a kind of RNA methyltransferase that catalyzes the methylation transfer to the N6-adenosine of RNA, serving as one of the key mediators in this process. However, the <i>METTL</i>23 gene has been poorly researched in pigs. In this study, we investigated the genetic effects of <i>METTL</i>23 single-nucleotide polymorphism(SNPs) on reproductive traits in Kele pigs. The DNA was extracted from 228 healthy multiparous Kele sows, and Sanger sequencing revealed three SNPs, g.4804958 G > T (intron 2), g.4805082 C > T (exon 2), and g.4806821 A > G (exon 3). The polymorphism information content (PIC) for each SNP was 0.264, 0.25, and 0.354, indicating moderate polymorphism (0.25 < PIC < 0.5) and providing genetic information. Linkage disequilibrium analysis showed no strong linkage disequilibrium between the three SNPs. The association analysis revealed that in the SNP g.4804958 G > T individuals with the GG genotype had a significantly higher number of piglets born alive, litter birth weight, number of weaned piglets, and weaning litter weight compared to those with the TT genotype (<i>p</i> < 0.05). Individuals with the GG genotype in the SNP g.4806821 A > G group had significantly higher litter birth weight and average birth weight than those with the AA genotype (<i>p</i> < 0.05). The H4H4 diplotype showed significant effects on the number of piglets born alive, litter birth weight, number of weaned piglets, weaning litter weight, and weaning weight (<i>p</i> < 0.05). Together, the <i>METTL</i>23 gene could be used as a candidate gene for the selection of reproductive traits in Kele pigs.