SLC25A1 and SLC25A4 are necessary for calcium homeostasis. A, Representative traces of mitochondrial Ca²⁺ uptake in permeabilized Hap1 cells challenged with 5 μm free Ca²⁺. Mitochondrial Rhod2 fluorescence (F/F₀) was measured as function of time (seconds). B, Quantification of the maximal rates of mitochondrial calcium influx ΔF/F₀/s in control and mutant Hap1 cell lines. Comparisons between genotypes were performed with one-way ANOVA followed by Fisher's multiple comparisons. C, qRT-PCR quantification of transcripts (x-axis) in Drosophila heads of control animals carrying the Actin-Gal4 driver alone or in combination with the UAS-RNAi for SLC25A1-sea or SLC25A4-sesB transgenes (n = 4, one-way ANOVA followed by Fisher's least significant difference comparison). D, mEJPs traces, (E) amplitudes, and (F) frequency at low and high extracellular calcium. The number of animals listed at the base of columns in E applies to F, and genotypes are listed on top of traces. E, P values for columns listed with italics at the base were determined by between-subjects ANOVA followed by Bonferroni–Dunn test: comparison a and b = 0.0014, a to c = 0.8421, e to f = 0.0008, e to g = 0.0026, f to g = 0.6967. G, PPF traces at low and high calcium concentrations. H, Amplitude of the first EJP (P1). The number of animals listed at the base of columns in H applies to I, and genotypes are listed on top of traces. I, Ratios of the two pulses. P values were determined by between-subjects ANOVA followed by Bonferroni–Dunn test.