Characterization of two SNPs (single nucleotide polymorphisms) in the porcine INSL3 gene and their exclusion as a common genetic basis of hernia inguinalis in pigs.

The INSL3 gene encoding Leydig cell insulin-like hormone is an important candidate gene for congenital disorders of the reproductive tract in pigs. Comparative sequencing using phenotypically hernia inguinalis affected and unaffected animals showed that the porcine gene is remarkably conserved. No polymorphisms were found in the two exons or in the intron. Two single-nucleotide polymorphisms (SNPs) were detected in the promoter region (G-224A and A-164C) of the sequenced pigs and fast screening methods were developed for large scale studies. Some significant breed differences exist for allele frequencies at both SNPs in the INSL3 gene. Screening of the two SNPs in a population of hernia inguinalis affected full and half sib piglets (n = 223) revealed that the SNPs can be excluded as a common genetic basis for this congenital disorder in this pedigree.