A) Sperm lysates were resolved by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), transferred to Immunoblot-P membranes, and probed with anti-phosphotyrosine (PY20) antibody. Lanes 1, 2, 3, 4, and 5 contained lysates from sperm that were incubated in absence of geldanamycin (Geld) as blank control for 0 h and 3 h, with dimethyl sulfoxide (DMSO, 0.1%, v/v) as the vehicle control, 1 µM Geld, or 20 µM Geld for 3 h under capacitation conditions. B) The phosphorylation levels were quantified by the intensity ratio of bands to that of the loading control, β tubulin. The results are expressed as means ±SEM (n = 5). a, compared to the blank control at 0 h, P<0.05; b, compared to the vehicle control at 3 h, P<0.05.