Polymorphisms in luteinizing hormone receptor and hypothalamic gonadotropin-releasing hormone genes and their effects on sperm quality traits in Chinese Holstein bulls

Abstract

Genes of hypothalamic-pituitary-gonadal axis play a key role in male reproductive performance. This study evaluated the polymorphisms of luteinizing hormone receptor (LHR) and hypothalamic gonadotropin-releasing hormone (GnRH) genes and their effects on sperm quality traits including semen volume per ejaculate (VOL), sperm density (SD), fresh sperm motility (FSM), thawed sperm motility (TSM), acrosome integrity rate (AIR), and abnormal sperm rate (ASR) collected from 205 Chinese Hostein bulls. The study bulls consisted of 205 mature Chinese Holstein, 27 Simmental, 28 Charolais, and 14 German yellow cattle. One single nucleotide polymorphism (SNP) (A883G) in exon 2 of GnRH and two SNPs (A51703G and G51656T) in intron 9 of LHR were identified in 274 bulls. Analysis of variance in 205 Chinese Holstein bulls showed that age had significant effect on both SD and FSM (P < 0.01), and ASR (P < 0.05). With regards to genotype and its interaction with age, only the SNP of G51656T in LHR gene had significant effect on SD (P < 0.05, P < 0.01; respectively). The association result showed that bulls with AG genotype had higher FSM than bulls with AA and GG genotype in LHR at 51,703 locus (P < 0.10), and bulls with GG genotype had higher SD than bulls with TT genotype in LHR at G51656T locus (P < 0.10). Phenotypic correlation among the traits revealed that significant negative correlations were observed between ASR and AIR (r = -0.736, P < 0.01), ASR and AIR (r = -0.500, P < 0.01). There were moderate positive correlations between VOL and SD (r = 0.422, P < 0.01), as well as FSM (r = 0.411, P < 0.01). In conclusion, LHR may be a potential marker for sperm quality of SD and FSM.

Polymorphisms in the bone morphogenetic protein 15 gene and their effect on sperm quality traits in Chinese Holstein bulls

“…Among them, age is one of the most important factors. Significant effects of age on FSM and ASR were observed in the present study (Table 3), and similar results were also obtained in our previous study (Sun et al, 2012). Researchers have found that sperm competition levels are positively associated with multiple sperm quality traits (Rowe and Pruett-Jones, 2011).…”

“…The significance of differences between genotypes was determined by the least-squares means method and compared by the Duncan multiple range test. Only factors that affected the records significantly (P < 0.05) were fitted in the final statistical model shown as follows (Sun et al, 2012):…”

“…Heritability values estimated for different sperm quality traits are of low-to-medium magnitudes (England et al, 2010;Wolf, 2010). The genetic parameters and the development of molecular biological techniques have led many researchers to use candidate gene studies to predict sperm quality traits in bulls Sang et al, 2011;Sun et al, 2012). However, there have been few studies reporting on the bone morphogenetic protein 15 (BMP-15) gene in bulls.…”

Differential expression of luteinizing hormone receptor, androgen receptor and heat-shock protein 70 in the testis of long-distance transported mice

“…Genetics is also an important factor that influences spermatogenesis and sperm quality. In another of our studies, we found that different genotypes of LHR had a significant effect on sperm density and fresh sperm motility, where the SNP site was located in an intron (Sun et al, 2012).…”

Effects of polymorphisms in the bovine growth differentiation factor 9 gene on sperm quality in Holstein bulls

“…It will, therefore, be meaningful to use a candidate gene approach to identify genes that influence semen quality traits. Recently, genes of the hypothalamic-pituitary-testicular axis have been widely studied as candidate marker genes for sperm quality in bulls (Dai et al, 2009;Sang et al, 2011;Sun et al, 2012); however, only a few studies have examined this for growth factor genes in bulls.…”