Table 1.

Ca²⁺ release in response to IP₃ in oocytes and eggs^a

Concentration of caged IP3 injectedb	Fluorescence after UV exposurec
	Oocytes	Eggs
0.1 μM	0.08 ± 0.04* (10)	0.9  ± 0.07 (10)
1 μM	0.35 ± 0.1* (6)	0.9  ± 0.15 (5)
10 μM	0.6 ± 0.07* (6)	0.8  ± 0.1 (6)

^a Data are expressed as the mean ± S.D. n = number of eggs tested. 

^b Stage VI oocytes were coinjected with 20-μM Ca²⁺ green dextran and caged IP₃ (concentrations given refer to the final concentration in the cytoplasm). Stage VI oocytes and mature eggs were exposed to UV light for 15 s to uncage the IP₃, and Ca²⁺ green fluorescence was monitored as in Figure 8. 

^c Data for Ca²⁺ green fluorescence in response to IP₃ are expressed as the area under the curve of photomultiplier current as a function of time for a 5-min period after the UV exposure; these values were normalized by dividing by (baseline current × 5 min). Data are presented this way rather than as peak amplitudes, because the peak sometimes occurred during the UV exposure. 

^* These values are significantly different from the values obtained in mature eggs (unpaired t test, p < 0.02).