Retinal Calcium Waves Coordinate Uniform Tissue Patterning of the Drosophila Eye

Optimal neural processing relies on precise tissue patterning across diverse cell types. Here, we show that spontaneous calcium waves arise among non-neuronal support cells in the developing Drosophila eye to drive retinal morphogenesis. Waves are initiated by Cad96Ca receptor tyrosine kinase signaling, triggering PLCγ-mediated calcium release from the endoplasmic reticulum. A cell-type-specific ‘Innexin-code’ coordinates wave propagation through a defined gap junction network among non-neuronal retinal cells, excluding photoreceptors. Wave intensity scales with ommatidial size, triggering stronger Myosin II-driven apical contractions at interommatidial boundaries in larger ommatidia. This size-dependent mechanism compensates for early boundary irregularities, ensuring uniform ommatidial packing critical for precise optical architecture. Our findings reveal how synchronized calcium signaling among non-neuronal cells orchestrates tissue patterning in the developing nervous system.