Figure 6.

Effects of urethane, procaine and NH₄Cl pretreatment on the Ca²⁺ signaling at fertilization. (A) Ca²⁺ response in the P. lividus eggs pretreated with 400 mM urethane for 5 minutes, (B) 10 mM procaine for 20 minutes and (C) 40 mM NH₄Cl (pH 9.0) for 30 minutes prior to fertilization. The Ca²⁺ trajectories after fertilization of the same batch of control and treated eggs are presented, and various parameters of the intracellular Ca²⁺ increase are shown with histograms as average values from three independent experiments. The experimental data are summarized in Table 2.