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.