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 (PCR-SSCP) 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.