Calcium signals play key roles in regulating diverse physiological processes. Metazoans have three main intracellular Ca2+ mobilizing messengers: IP3, cADPR and NAADP. Both cADPR and NAADP, which are generated by the same enzymes (ADP-rybosil ciclases, ARCs), were identified as Ca2+ mobilizing messengers using the sea urchin egg homogenate. This system continues to be a vital tool for investigating the mechanism of action of these two messengers. Although cADPR and NAADP have been implicated in diverse physiological processes and it has been shown that the loss of the ARC enzyme in the mouse leads to disease states, including diabetes and metabolic disturbances, the molecular mechanisms underlying ARC action and regulation are unknown. We are gaining key insights into the mechanisms of action of these messenger protein families using sea urchins as a model system. By studying the abnormalities in developmental processes caused by these proteins, we expect to gain vital insights into the link between cADPR and NAADP induced Ca2+ signals and the regulation of physiological processes in all cells.