Fig. 1. PKC inhibitors dose-dependently inhibit the motility of intact sea urchin spermatozoa. Lytechinus pictus spermatozoa were pre-incubated in IM medium with one of the following inhibitors – chelerythrine, calphostin C or Gö6976 – and then diluted in ASW containing the same amount of inhibitor. The percentage of motile cells (A) and the spermatozoa velocity (B) were evaluated over a 15 min period as described in the Materials and methods. Values are means ± s.e.m. from three different experiments.