A Genome-Wide Association Study Links AEBP2 to Litter Size in Meishan Pigs

This study combined liquid-phase chip technology with a genome-wide association study (GWAS) to identify candidate functional genes for litter size in Meishan pigs. Genotyping of 198 Meishan sows using the "Shenxin No. 1" 60K porcine SNP chip, followed by quality control with PLINK v1.90, yielded 31,430 autosomal SNPs. Principal component analysis revealed no significant population stratification. Using a mixed linear model in GEMMA (v 0.98.1), we identified 9 significant SNP loci and 52 candidate genes on chromosomes 5 and 14, including AEBP2, P2RX2, ANKLE2, PGAM5, and EP400, which are implicated in embryonic development, ovarian function, and cell proliferation. Isolated porcine ovarian granulosa cells were validated by FSHR immunofluorescence, showing 99% purity. Overexpression of AEBP2 significantly upregulated its protein expression (Western blot) and promoted granulosa cell proliferation (CCK-8). Collectively, these results pinpoint potential candidate genomic regions and functional genes associated with litter size and suggest that AEBP2 may enhance reproductive performance by promoting granulosa cell proliferation and follicular development. This provides new targets for elucidating the genetic mechanisms underlying the high fecundity of Meishan pigs and for advancing molecular breeding efforts.