Fig. 5. The role of phosphoinositide 3-kinase in PAF-induced Ca²⁺-influx as assessed by Mn²⁺-quenching of Fura-2. The relative fluorescence (arbitrary units) of Fura-2 loaded two-cell embryos measured at 360 nm in perfusion media in which calcium has been replaced with 0.1 mM Mn²⁺. The lines in each graph show the mean traces from the number of embryos shown in brackets. The boxed areas on the x-axis represent the time interval that the treatments indicated were applied.