Fig. 5.

Fig. 5.

EEC mitochondrial activity changes during development. (A) Schematic showing in vivo imaging to trace the EEC cytoplasmic and mitochondrial Ca²⁺ in the same zebrafish from 3 dpf to 6 dpf. The commensal microbiota colonizing conventionally raised zebrafish was used. EECs from nine zebrafish were traced and analyzed. (B-E″) Confocal projections of the same Tg(neurod1:Gcamp6f); Tg(neurod1:mitoRGECO) zebrafish at 3 dpf, 4 dpf, 5 dpf, and 6 dpf. The EEC cytoplasmic Ca²⁺ level is represented via the Gcamp6f fluorescence (green). The EEC mitochondrial Ca²⁺ level is displayed through mitoRGECO fluorescence (magenta). (F-H) EECs from the same zebrafish were analyzed from 3 dpf to 6 dpf. EEC mitochondria-to-cytoplasmic Ca²⁺ ratio, cytoplasmic Ca²⁺ and mitochondrial Ca²⁺ were quantified. (I-K) Pooled EECs from nine zebrafish were analyzed from 3 dpf to 6 dpf. Mitochondria-to-cytoplasmic Ca²⁺ ratio, cytoplasmic Ca²⁺ and mitochondrial Ca²⁺ were quantified. Each dot in F-K represents an individual EEC. Dashed lines indicate the changes of EEC cellular and mitochondrial calcium activity from 3 dpf to 7 dpf. Data are mean±s.d. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001 (one-way Anova followed by Tukey's post test). Scale bars: 50 μm.