title: Multiple mechanisms modulate distinct cellular susceptibilities toward apoptosis in the developing Drosophila eye.
abstract: Although apoptosis is mechanistically well understood, a comprehensive understanding of how cells modulate their susceptibility toward apoptosis in a developing tissue is lacking. Here, we reveal striking dynamics in the apoptotic susceptibilities of different cell types in the Drosophila retina over a period of only 24 hr. Mitotic cells are extremely susceptible to apoptotic signals, while postmitotic cells have developed several strategies to promote survival. For example, photoreceptor neurons accumulate the inhibitor of apoptosis, Diap1. In unspecified cells, Cullin-3-mediated degradation keeps Diap1 levels low. These cells depend on EGFR signaling for survival. As development proceeds, developmentally older photoreceptors degrade Diap1, resulting in increased apoptosis susceptibility. Finally, R8 photoreceptors have very efficient survival mechanisms independent of EGFR or Diap1. These examples illustrate how complex cellular susceptibility toward apoptosis is regulated in a developing organ. Similar complexities may regulate apoptosis susceptibilities in mammalian development, and tumor cells may take advantage of it.
authors: Department of Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA. Electronic address: y.fan@bham.ac.uk.
authors: Yun
authors: Y
authors: Fan
authors: Department of Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA. Electronic address: andreas.bergmann@umassmed.edu.
authors: Andreas
authors: A
authors: Bergmann
mesh_terms: D000818:Animals; D017209:Apoptosis; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D005123:Eye / Q000254:growth & development* / Q000378:metabolism / Q000473:pathology*; D018507:Gene Expression Regulation, Developmental; D018773:Genes, erbB-1; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism; D008938:Mitosis / Q000502:physiology; D009474:Neurons / Q000378:metabolism / Q000473:pathology*; D010786:Photoreceptor Cells / Q000378:metabolism / Q000473:pathology*; D015398:Signal Transduction
chemical_list: C111891:DIAP1 protein, Drosophila; D029721:Drosophila Proteins; D051034:Inhibitor of Apoptosis Proteins; D020169:Caspases