Figure 4. Extracellular Ca²⁺ entry obtained on dSEPT7 reduction requires functional dOrai channels.

(a,b) Wing-posture defects (a) and reduced flight duration (b) in flies with pan-neuronal knockdown of dSTIM (dSTIM-IR) was rescued by dSEPT7 reduction with either a single copy of the deficiency allele or RNAi-mediated targeted knockdown in neurons. N≥30; **P<0.01, Mann–Whitney U-test; flight duration of dSTIM knockdown flies with reduced dSEPT7 using either dSEPT7 het or dSEPT7-IR compared with that of dSTIM knockdown flies. (c) Reduced SOCE on dSTIM knockdown in primary neurons was restored on dSEPT7 reduction; N≥150 cells. Pan-neuronal elav^C155GAL4 was used to drive expression of dSTIM-IR. (d) Quantification of peak ΔF/F values obtained during SOCE (300–600 s) for the indicated genotypes; **P<0.001, Mann–Whitney U-test with Bonferroni correction. (e) Reduced SOCE obtained by knockdown of dOrai was not rescued on dSEPT7 reduction. Traces represent the mean (±s.e.m.) ΔF/F values obtained at each time point during TG-induced ER store Ca²⁺ depletion and SOCE for the indicated genotypes (N≥150 cells). Pan-neuronal elav^C155 GAL4 was used to drive expression of dOrai-IR. (f) Reduced SOCE obtained by expression of dOrai^E180A was not rescued by dSEPT7 reduction; N≥150 cells. Pan-neuronal elav^C155GAL4 was used to drive expression of dOrai^E180A. Control refers to neurons with the dOrai^E180A transgenic construct, but no GAL4 driver, resulting in no expression of the transgene. (g) Box plots quantifying the peak ΔF/F values for SOCE (300–600 s) computed from the Ca²⁺ traces shown in f **P<0.001, Mann–Whitney U-test with Bonferroni correction. (h) Reduced SOCE obtained in neurons homozygous for a hypomorphic dOrai mutant allele (dOrai³ hom or dOrai^3/3) was not rescued on dSEPT7 reduction. Traces represent the mean (±s.e.m.) ΔF/F values obtained at each time point during TG-induced ER store Ca²⁺ depletion and SOCE for the indicated genotypes (N≥150 cells). dOrai³ het control refers to neurons heterozygous for the dOrai³ hypomorphic allele (recessive). (i) Box plot quantifying the peak ΔF/F obtained during SOCE in the indicated genotypes. **P<0.001, Mann–Whitney U-test. (j) K–S plot analysing the peak ΔF/F obtained during SOCE in the indicated genotypes. P<0.001, K–S test.