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 (LH beta) 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 (PCRSSCP) and Sanger sequencing method is used to study genetic variability in LH beta 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 LH beta gene with semen quality in 109 and LH concentrations in 80 Murrah bulls. Results: LH beta gene was found to be polymorphic. Total six SNPs were identified in LH beta 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 LH beta gene with semen quality parameters and LH concentrations indicated the possibilities of using LH beta as a candidate gene for identification of markers for semen quality traits and LH concentrations in Murrah buffaloes.