cSrc activation is required for acrosomal exocytosis.
A, sperm were capacitated in the presence or absence of SU6656 (SU). Samples were prepared for Western blot analyses performed with anti-Tyr(P) (clone 4G10) antibodies. NC, non-capacitating; Cap, capacitating. B, sperm were incubated under capacitating conditions in the presence of different concentration of SU6656 (SU) or SKI606 (SKI) for 60 min. When indicated, sperm were challenged with 20 μm progesterone and incubated further for 30 min before assessment of the acrosomal status by fluorescence microscopy. Alternatively, SU6656 or SKI606 was added after 60 min of capacitation, followed 3 min later by 20 μm progesterone, and incubated further for 30 min. C and D, sperm were incubated under capacitating conditions in the presence of different concentrations of SU6656 for 60 min. When indicated, sperm were challenged with 20 μm progesterone and incubated further for 30 min before assessment of the acrosomal status by flow cytometry using sperm expressing EGFP under the acr promoter, as shown in D. AI, acrosome intact; AR, acrosome reacted. Data represent mean ± S.E. of at least three independent experiments. *, p < 0.01.