Mutatuion in the porcine SERPINA7 gene and its association with boar fertility

Abstract

The porcine SERPINA7 gene is considered as a positional candidate gene responsible for testis size for its location on X chromosome and its biologically critical role in the development of testis. A nonsynonymous polymorphism (His226Asn or C678A) in the ligand-binding domain of SERPINA7 has been identified, which alters SERPINA7's affinity to thyroxine and is closely associated with testis size. In this study, a primer mutagenesis strategy was developed to genotype this polymorphism in Chinese indigenous pigs and some western commercial pigs. The C allele existed in all tested Chinese indigenous and wild pigs, while the A allele is specific for western commercial breeds, indicating the occurrence of the mutation is of western origin. The correlation of this polymorphism with different boar fertility traits was assessed using a White Duroc X Erhualian intercross which included 110 F2 mature boars. The results showed that the C678A polymorphism was closely associated with testis weight and epididymis weight ( P 0.0001 and P = 0. 0016, respectively) with significant heavier testis weight and epididymis weight in boars carrying the A allele than boars with the C allele. A significant correlation was also observed between this polymorphism and total sperm in the ejaculate (P0.01) as well as semen volume (P0.05). No statistically significant association of the C678A polymorphism with sperm concentration and sperm motility was found.