Fig. 4: Calcium oscillations of EECs regulate NPF secretion.

a, b Representative heatmap records of GCaMP intensity of 10 individual EECs a and quantification of calcium peaks in EECs b within 10 min (660 frames) under different feeding conditions. c Schematic representation of the regulation of Ca²⁺ flux. IP3R causes release of Ca²⁺ (red dots) from the ER to the cytoplasm. Stim senses the decline of Ca²⁺ in the ER, and induces extracellular Ca²⁺ influx into the cytoplasm, forming a high [Ca²⁺]. Excessive cytoplasmic Ca²⁺ is pumped into the ER by SERCA or out of the cell by PMCA, resulting in a decrease in cytoplasmic [Ca²⁺]. d, e Quantification of calcium peaks in EECs d and representative heatmap records of GCaMP intensity of 10 individual EECs e of flies with the indicated genotypes within 10 min. f, g Representative images f and quantification g of pANF-EMD staining in EECs of flies with the indicated genotypes. n = 30 in each genotype. h, i Representative images h and quantification i of NPF staining in EECs of flies with the indicated genotypes. n = 75 in each genotype. j Food intake of flies of control and the indicated genotypes. Data are represented as mean ± SD. Significance was determined using two-sided unpaired t-test b, d, g, I, j. n, number of EECs a, b, d, g, i, or number of groups performed for quantification of food intake (5 flies in each group) j. Source data are provided as a Source Data file. Scale bars, 20 μm.