College of Veterinary and Animal Sciences, SVPUAT, Meerut, India

Capaciatation and acrosome reaction are two very important processes for achieving the fertilizing competence in spermatozoa. In our study acrosome reaction in capacitated murrah buffalo spermatozoa was induced in the absence (control) or presence of LPC (positive control, 100g/mL) or inducers such as Spermine-NONOate (100 μM), progesterone (P4, 20 μM), and estradiol (E2, 50 μM). Progesterone induced significantly (P<0.05) highest percentage of AR (53.86±0.30%) followed by LPC (52.07±0.46%), 17-β Estradiol (45.13±0.15%) and spermine-NONOate (43.85±0.42%). Subset of protein p32, p38, p45, p49, p80 and p105 were significantly (P<0.05) more phosphorylated in progesterone also as compared to the spermine-NONOate followed by LPC. In comparison to progesterone and LPC-induced phosphorylation, p69 was higher phosphorylated in the spermine-NONOate treated spermatozoa. This study came to the conclusion that the agonist-induced acrosome response in buffalo spermatozoa increased protein tyrosine phosphorylation of the group of proteins described above.