Figure 6.

Effect of GdCl₃ on the Ca²⁺ influx set after gametic fusion. Ca²⁺ fluxes were first recorded during IVF before addition of GdCl₃ to the fusion medium. As in Fig. 3, time 0 is chosen arbitrarily as the time of gametic fusion. The single arrow indicates the onset of a Ca²⁺ influx. GdCl₃ (10 μM final concentration) was then added (arrow with asterisk). A typical recording is shown (n = 17). GdCl₃ inhibits 93.07% of the Ca²⁺ influx induced by fusion. A, B, C, and D refer to the time when the pictures (Lower) were taken. The following events are depicted: (A) egg cell before fusion (male gamete position is shown by white arrow); (B) egg cell after fusion, just when contraction has started; and (C) strong egg cell contraction, which was abolished immediately (D) by GdCl₃ addition.