Role of IP3 receptor in development

IP3 receptor is a Ca2+ release channel localized on the endoplasmic reticulum. IP3 receptor is composed of three isoforms, which are expressed in various cells and tissues, and play variety of roles throughout development. I here describe the role of IP3 receptor from oogenesis, meiotic maturation and fertilization. I also describe the Ca2+ signaling at meiosis and mitosis, and especially the role in early embryogenesis to determine dorso-ventral axis formation. Loss of function mutation of type 1 IP3 receptor in mouse, both by gene targeting and spontaneous mutations shows severe ataxia and other phenotypes. Interestingly, double knockouts of type 1 and type 2 exhibit cardiogenesis arrest and that of type 2 and type 3 results in exocrine secretion deficit. IP3R of Drosophila or Caenorhabditis elegans is single gene and mutation results severe phenotype of behavior. All the data described here show that IP3Rs are essential for life and abnormality of IP3Rs results in severe abnormality in its structure and function of organism.