Intercellular calcium waves are controlled by morphogen signaling during organ development

Spontaneous and dramatic intercellular calcium waves are frequently observed during organ development, but are poorly understood. Calcium ions are ubiquitous second messengers that carry out a wide-range of functions, including the regulation of cell proliferation, metabolism and death. Consequently, regulation of calcium signaling encodes a significant portion of the cellular decision making state of cells through both amplitude and frequency-dependent regulation of transcription factors and key regulatory enzymes. Here we report that intercellular calcium waves exhibit spatiotemporal patterns at the organ-level using a quantitative image analysis pipeline. Intercellular calcium waves in the Drosophila wing disc require a specific phospholipase C, Plc21C. Further, we demonstrate that the morphogen signaling pathway, Hedgehog, controls frequencies of calcium oscillations uniformly in the tissue and is required for non-uniform spatial patterning of oscillation amplitudes. Thus, the dynamics of spontaneous intercellular calcium waves are regulated by morphogenetic signaling. Intercellular calcium waves propagate information at the organ-scale that reflects the differentiation state of the developing wing disc.