FIG. 4.

Farnesol treatment results in acrosome loss in spermatozoa. (A) Spermatozoa were treated for 1 h with increasing concentrations of farnesol. The sperm acrosomes were detected by fluorescence microscopy using FITC-PSA, which binds to intact acrosomal membranes. Intact acrosomes were identified by a uniform fluorescence in the acrosomal region of the sperm head, whereas acrosome loss was revealed by absent fluorescence or equatorial segment staining (arrows). Note that sperm with defective acrosomes are already visible after treatment with 5 μM farnesol (scale bars represent 5 μm). (B) The proportion of sperm with intact acrosomes after 1 h of incubation with farnesol decreases in a dose-dependent manner. The percentage of spermatozoa with intact acrosomes in the medium controls plus solvent was set to 100%. Results are the means ± SDs from at least three independent experiments.