Effect of polymorphisms in the FAM151B gene on testis-related trait parameters in Hu sheep

The family with sequence similarity 151 member B (FAM151B) gene family is widely distributed in animals. This gene family encodes proteins belonging to the phosphodiesterase superfamily which plays a role in hydrolyzing intracellular second messengers, and affects the proliferation of Sertoli cells in the testis by degrading intracellular cAMP or cGMP content, thereby affecting the sperm production capacity of the testis. In this study, mutations in the FAM151B gene were screened in 491 Hu sheep to analyze the association among FAM151B gene polymorphisms testicular traits, and sperm-related parameters. A synonymous mutation (5: g.77976636 C>T), was detected in FAM151B, resulting in three genotypes, namely, CC, TT, and TC, with genotypic frequencies of 0.33, 0.05, and 0.62, respectively. This synonymous mutation was found to be significantly correlated with testicular weight, long testicular circumference, short testicular circumference, epididymal weight, and sperm count (p <0.05). In addition, individuals with CC genotypes had significant reproductive performance advantages compared with those with TC and TT genotypes. The current study shows that the FAM151B gene may play important roles in testicular development, and its SNPs are associated with testicular parameters, and sperm count, which provides important indicators for ram selection at early stage.