Association analyses of porcine SERPINE1 reveal sex-specific effects on muscling, growth, fat accretion and meat quality

The serpin peptidase inhibitor, clade E (nexin, plasminogen activator inhibitor type 1), member 1 (SERPINE1) gene encodes plasminogen activator inhibitor type 1 (PAI), which is the major physiological inhibitor of tissue-type and urokinase-type plasminogen activators and plays a role in obesity and insulin resistance in women but not in men. We detected SNP FN396538:g.566G>A in intron 3 and a non-synonymous substitution NM_213910:c.612A>G in exon 3 (p.Ile159Val) and mapped the gene to position 8.4 cM on the linkage map of chromosome 3. Association analyses were conducted on the 12th15th generation of the Meishan X Large White (MLW) cross (n = 565), with records for weight at the end of test, lifetime daily gain, test time daily gain, loin depth and backfat depth, as well as on a European wild boar X Meishan (W X M) F2 population (n = 333) with 47 traits recorded for carcass composition and meat quality. Analyses performed across the entire MLW population or in the male animals did not show any trait significantly associated with the loci studied. In female animals, both SNPs were associated with loin depth at nominal P < 0.05 with adjusted P values equal to 0.051 (g.566) and 0.057 (c.612). Differences between homozygotes were up to 0.65 SD. In the entire W X M population and female animals, SERPINE1 was significantly associated at adjusted P < 0.05 in descending order with muscling, growth and fat accretion and in male animals with meat quality (R-value). In the studied populations, allele effects were in opposite directions, which implies that the SNPs are markers that are in linkage disequilibrium with a causative mutation.