Reproduction, Fertility and Development Reproduction, Fertility and Development Society
Vertebrate reproductive science and technology

Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

Splicing-related SNP of RABL2B jeopardizes semen quality in Chinese Holstein bulls

Xiuge Wang , Xiaohui Cui , Yan Zhang , Haisheng Hao , Zhihua Ju , Deyu Liu , Qiang Jiang , Chunhong Yang , Yan Sun , Changfa Wang , Jinming Huang , huabin zhu

Abstract

RABL2B is a member of a poorly characterized clade of RAS GTPase superfamily, which plays an essential role in male fertility, sperm intra-flagellar transport, and tail assembly. In this study, we identified a novel RABL2B splice variant in bovine testis and sperm; this splice variant, designated as RABL2B-TV, is characterized by exon 2 skipping. Moreover, a single-nucleotide polymorphism (SNP) c.125 G > A was found within the exonic splicing enhancer (ESE) motif, indicating that SNP caused the production of RABL2B-TV aberrant splice variant; we demonstrated this phenomenon by constructing pSPL3 exon capturing vector with different genotypes and transfecting these vectors in cells. Expression of RABL2B-TV transcript was lower in high-performance bull semen than in low-performance bull semen. Association analysis showed that sperm deformity rate was significantly lower in Chinese Holstein bulls with GG or GA genotype than in bulls with AA genotype (P < 0.05); additionally, the initial sperm motility was significantly higher in individuals with GG or GA genotype than in individuals with AA genotype (P < 0.05). Our findings suggest that the difference in semen quality in bulls with different RABL2B genotypes are generated via an alternative splicing mechanism caused by a functional SNP within the ESE motif.

RD17111  Accepted 18 April 2017

© CSIRO 2017