Our research focuses on cell-cell signaling events that lead to intracellular calcium release. We integrate in vivo image analysis coupled with molecular-genetic tools to elucidate the role of calcium-dependent signaling networks critical in developmental processes such as body plan formation and organogenesis in the zebrafish. The zebrafish model system for vertebrate developmental biology has many attributes including genetics, rapid development and translucent embryos. We defined a class of Wnt signaling ligands that modulate intracellular calcium release and are investigating the mechanisms by which this Wnt/calcium class mediates its biological effect on the developing embryo. As inappropriate Wnt signaling has been associated with a high frequency of tumors, we are also investigating spontaneous tumor formation in genetic backgrounds that disrupt the function of Wnt/calcium class ligands. Additionally, we have determined that the calcium release requires G-protein signaling. To identify potential intracellular regulators of calcium release dynamics, we are characterizing members of the regulators of G-protein signaling protein family. We have cloned and characterized a few members of the RGS family and find they have essential roles in sensory neuron and somite patterning. Due to the remarkable conservation of developmental processes and mechanisms among vertebrates, we also use zebrafish as a model for human disease and test candidate genes. Of note are studies involving retinal degeneration and Bardet-Biedl Syndrome.