Genetic polymorphisms in ESR and FSHβ genes and their association with litter traits in Large White pigs

The estrogen receptor (ESR) gene and follicle-stimulating hormone β (FSHβ) gene are responsible for litter traits. The present study aimed to verify the polymorphisms of ESR and FSHβ and assess their effects on the litter traits in 201 Large White pigs. Four SNPs (g.C669T, g.A1296G, g.C1665T and g.A1755G) were found in ESR. The TT genotype at g.C1665T locus and AA genotype at g.A1755G locus could significantly increase the total litter size of the first litter of American Large White pigs (p < 0.05). Eight SNPs were found in exon 3 of FSHβ. The AA genotype at g.A511G locus, AA and AG genotypes at g.A617G locus, CC and CT genotypes at g.C630T locus, CT and TT genotypes at g.C652T locus, CT and TT genotypes at g.C735T locus, AA and AG genotypes at g.A746G, AA and AG genotypes at g.A921G and CT genotype at g.C678T could significantly increase the litter size of different strains of Large White pigs (p < 0.05). Our study revealed that the genetic variations of ESR and FSHβ were closely related to the litter trait of Large White pigs. Therefore, ESR and FSHβ genes could be used as molecular markers for the genetic selection of Large White pigs.