Luteinizing hormone beta gene polymorphism and its effect on semen quality traits and luteinizing hormone concentrations in Murrah buffalo bulls

OBJECTIVE: Present investigation was aimed to study the Single Nucleotide Variants of the luteinizing hormone beta (LHβ) gene and to analyze their association with the semen quality (fresh and post-thawed frozen semen) and luteinizing hormone (LH) concentrations in Murrah buffalo bulls. METHODS: Polymerase chain reaction–single stranded conformational polymorphism (PCR–SSCP) and Sanger sequencing method is used to study genetic variability in LHβ gene. LH assay was carried out using enzyme-linked immunosorbent assay method. A fixed general linear model was used to analyze association of single nucleotide polymorphism (SNP) of LHβ gene with semen quality in 109 and LH concentrations in 80 Murrah bulls. RESULTS: LHβ gene was found to be polymorphic. Total six SNPs were identified in LHβ gene g C356090A, g C356113T, g A356701G, g G355869A, g G356330C, and g G356606T. Single Stranded Conformational Polymorphism variants of pattern 2 of exon 1+pattern 2 of exon 2+pattern 1 of exon 3 had highly significant (p<0.01) effect on sperm concentration (million/mL), percent mass motility, acrosome integrity and membrane integrity in fresh and frozen semen whereas significant (p<0.05) effect was observed on percent live spermatozoa. SSCP variants of pattern 2 of exon 1+pattern 2 of exon 2+pattern 1 of exon 3 had highly significant (p<0.01) effect on luteinizing hormone concentrations too. CONCLUSION: The observed association between SSCP variants of LHβ gene with semen quality parameters and LH concentrations indicated the possibilities of using LHβ as a candidate gene for identification of markers for semen quality traits and LH concentrations in Murrah buffaloes.