Genetic polymorphism of aquaporin 7 gene and its association with semen quality in Surti bulls

Abstract

The present study was carried out with the aim to characterise Aquaporin 7 (AQP7) gene and to investigate the association of genetic variants with semen quality in Surti bulls. A total of 21 Surti bulls maintained at Centralized Semen Collection Centre, Dharwad, Karnataka were included in the study. Single Nucleotide Polymorphisms (SNPs) in the coding region of AQP7 gene were identified through polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis and direct sequencing. A total of 14 different SSCP variants were found in exonic regions along with the exon-intron boundaries (amplicons) of AQP7 gene. Statistical analysis was done by SAS 9.3. Analysis of exons (amplicons) 1, 4, 5, 7 and 8 revealed two, three, four, three and two unique SSCP band patterns, respectively. SSCP variants of exon 1 were found to have significant (P<0.05) effect on Hypo-osmotic swelling reactivity in frozen semen. SSCP variants of exons 5 and 8 were found to have significant (P<0.01) effect on sperm viability in fresh semen and Post thaw motility, respectively. The study indicated high degree of genetic variability in AQP7 gene in Surti bulls. The observed SSCP variants having association with semen parameter shows the possibility of using AQP7 gene as a candidate gene for identification of markers for semen quality traits in buffaloes.