In vivo relevance of intercellular calcium signaling in Drosophila wing development

Recently, organ-scale intercellular Ca 2+ transients (ICTs) were reported in the Drosophila wing disc. However, the functional in vivo significance of ICTs remains largely unknown. Here we demonstrate the in vivo relevance of intercellular Ca 2+ signaling and its impact on wing development. We report that Ca 2+ signaling in vivo decreases as wing discs mature. Ca 2+ signaling ex vivo responds to fly extract in a dose-dependent manner. This suggests ICTs occur in vivo due to chemical stimulus that varies in concentration during development. RNAi mediated inhibition of genes required for ICTs results in defects in the size, shape, and vein patterning of adult wings. It also leads to reduction or elimination of in vivo Ca 2+ transients. Further, perturbations to the extracellular matrix along the basal side of the wing disc stimulates intercellular Ca 2+ waves. This is the first identified chemically defined, non-wounding stimulus of ICTs. Together, these results point toward specific in vivo functions of intercellular Ca 2+ signaling to mediate mechanical stress dissipation and ensure robust patterning during development.