Identification of Four SNPs in LHB Gene and Their Associations with Sperm Qualities of Chinese Buffaloes

Luteinizing hormone beta polypeptide (LHB) gene has been considered important for sexual behavior and has associations with sperm quality. In this study, four SNPs (g.276T>C, g.377A>C, g.401T>C, and g.412A>G) were detected in the LHB gene of 165 water buffaloes by direct sequencing and identification of overlap peaks, each of which was associated with at least one sperm quality trait of ejaculate volume, sperm concentration, post-thaw sperm motilities, and sperm abnormalities by chi-square analysis. Among them, g.276T>C was associated with ejaculate volume (F=2.857, p<0.05), sperm concentration (F=2.052, p<0.05), and post-thaw sperm motilities (F=3.480, p<0.05); g.377A>C was related to ejaculate volume (F=4.178, p<0.05), g.401T>C had a marker effect on sperm abnormalities (F=3.332, p<0.05), g.412A>G was associated with sperm concentration (F=3.579, p<0.05), and sperm abnormalities (F=3.408, p<0.05). Furthermore, four haplotypes (H1: ACG, H2: CCG, H3: CTA, H4: CCA) were generated by linkage disequilibrium analysis, which composed seven genotypes. Among them, the buffaloes with combined genotype H2H2 had the higher ejaculate volume and the individuals with the combined haplotypes H1H4 had higher sperm concentration. In summary, our study showed that there was a significant association between SNPs of LHB gene and Chinese water buffalo sperm quality traits. To the best of our knowledge, this is the first report addressing the associations between the SNPs in the LHB gene and the sperm qualities of Chinese buffaloes.