Figure 4. Analysis of MII eggs and GV oocytes lacking both STIM1 and STIM2.

Ratiometric Ca²⁺ imaging of control and Stim1/2 cKO eggs was performed during IVF. (A) Representative traces are shown. (B–E) Analysis of Ca²⁺ oscillation patterns, n=28–31 eggs per genotype over 4 replicate experiments. (B) Length of first transient. (C) Amplitude of first transient. (D) Oscillation frequency. (E) Persistence of oscillations to the end of the 60 min imaging period. (F–I) Measurements of ER Ca²⁺ stores and Ca²⁺ influx 35–40 min after thapsigargin (Tg)-induced ER store depletion in Stim1/2 cKO and control eggs, n=23 eggs per genotype over 4 replicate experiments. (F,G) Graphs of ER Ca²⁺ stores indicated by area under the curve (F) and peak amplitude (G). * p < 0.05, Mann Whitney. (H,I) Graphs of Ca²⁺ entry following store depletion indicated by area under the curve (H) and peak amplitude (I). (J–M) Measurements of ER Ca²⁺ stores and Ca²⁺ influx 35–40 min after thapsigargin (Tg)-induced ER store depletion in Stim1/2 cKO and control GV oocytes, n=23–24 oocytes per genotype over 4 replicate experiments. (J,K) Graphs of ER Ca²⁺ stores indicated by area under the curve (J) and peak amplitude (K). (L,M) Graphs of Ca²⁺ entry following store depletion indicated by area under the curve (L) and peak amplitude (M). (N–P) Fertility of female Stim1/2 cKO mice. (N) Average litter size. (O) Days to first litter. (P) Total number of live pups.