SNP Identification for Intron 3 of PTGS2 Gene and Its Association with Reproductive Traits in Large White Sows

Purpose The aim of the present study was to reveal the association of the polymorphisms of prostaglandin-endoperoxide synthase 2 (PTGS2) gene with sow reproductive traits.

Method The single nucleotide polymorphisms (SNPs) within the intron 3 of PTGS2 gene were detected by PCR product directed sequencing in 401 Large White (LW) sows. Combing the data of 1 786 litters reproductive performance, the effects of each locus and haplotype combinations for multiple loci on five reproductive traits were analyzed by least square model.

Results Three closely linked SNPs, G227A, A392C and T409C were identified within the intron 3 of PTGS2 gene in LW pigs. The highest frequency was presented for the alleles G, A, T, the homozygous genotypes GG, AA, TT, haplotype GAT and the combination GAT/GAT; the relative abundant genetic diversity was showed on the three loci, and the heterozygosities of the loci were ranged from 0.320 9 to 0.353 6 in LW pigs. Sows with genotype GA at G227A, AC at A392C, TC at T409C locus, and haplotype GAT had higher total number born (TNB), number of piglets born alive (NBA) and number of alive piglets at 21^st day than those of the other genotypes and haplotypes significantly (P<0.05 orP<0.01); the genotype AA, CC, CC of the three loci and haplotype combination GCC/GCC had significant increasing effects on the litter weights at 21^st day (P<0.05 orP<0.01).

Conclusion The results further enriched the SNP markers of porcine PTGS2 gene, and preliminary confirmed that the PTGS2 gene was significantly associated with reproductive traits of sows, but the specific effects might be variety on different traits and in different breeds or populations.