TRPV3 channels mediate Sr2+ influx and subsequent egg activation. A. Results of whole-cell patch -clamp recording (37°C) of MII eggs from heterozygous (TrpV3+/−, green symbols, n=4) and TrpV3-KO (TrpV3−/−, blue symbols, n=4) mice. Current-voltage (I–V) relation in 10 mM SrCl2. Inset: Averaged current at −80 mV. B. Oscillations induced by Sr2+ in a TrpV3+/− egg (green line, n=6), but not in a TrpV3-KO egg (blue line, n=8). C. Sr2+ induces cleavage in V3-Het (left) but not in V3-KO (right) eggs. D. Percentage of cleaved eggs after 24 h of 10 mM Sr2+ treatment. Numbers of 2, 3, or 4-cell blastomeres/total number of eggs is indicated. Data are averages ± S.E.M.