[
Ernst Schering Res Found Workshop,
2000]
The proliferation of cells is an integral part of development and tissue homeostatsis in multicellular animals(reviewed by Raff 1996; Folletee and O'farrel 1997). Two opposing processes, the division of cells on one hand and the programmed death of cells on the other hand, determine the overall rate of cell proliferation, The proper regulation of these two physiological processes is therefore a crucial aspect of development and of tissue homeostatsis(reviewed by Edgar and Lehner 1996; Shrr 1997;Jacobson et al. 1997). While the importance of the process of cell division has long been recognized, the role and extent of programmed cell death, or apoptosis, has only been realized within the last decades (Glucksmann 1950; Kerr et al. 19972). Massive programmed cell death occurs, for instance, during the development of the nervous system and in the immune system: more than 50% on all neurons and oligodendrocytes formed in the periperal and central vertebrate nervous system undergo programmed cell death neurogenesis...
[
Cell Calcium,
2011]
IP receptor is a Ca(2+) release channel localized on the endoplasmic reticulum. IP(3) 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 IP receptor from oogenesis, meiotic maturation and fertilization. I also describe the Ca(2+) 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 IP 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. IPR of Drosophila or Caenorhabditis elegans is single gene and mutation results severe phenotype of behavior. All the data described here show that IPRs are essential for life and abnormality of IP(3)Rs results in severe abnormality in its structure and function of organism.