Fig. 3.

IP₃R1 degradation occurs in the absence of [Ca²⁺]_i oscillations. MII eggs were incubated in medium containing 2 μ MBAPTA-AM for 30 min prior to ICSI or injection of mPLCζ mRNA. Despite precluding egg activation, BAPTA-AM treatment did not affect IP₃R1 degradation by ICSI (A). BAPTA-AM treatment also did not affect IP₃R1 degradation induced by injection of PLCζ mRNA (0.5 μg/μl) (B), although it greatly reduced the[Ca²⁺]_i oscillations induced by them RNA (inset) (C). IP₃R1 degradation in response to PLCζ mRNA(0.1 μg/μl) injection (D) was not prevented or modified by the absence of [Ca²⁺]_i oscillations, a condition that in this case was accomplished by culturing eggs innominal Ca²⁺-free medium and LatB (E). Eggs were injected with PLCζ mRNA in normal media, but within 10 min of injection eggs were moved to Ca²⁺-free media supplemented with LatB. Arrows in (C) and (E) denote time of injection.