Multiple mechanisms modulate distinct cellular susceptibilities toward apoptosis in the developing Drosophila eye
Related Experiment Video
Updated: Apr 27, 2026
Live-imaging of the Drosophila Pupal Eye
Published on: January 12, 2015
1Department of Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
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.
Insights
Cell susceptibility to apoptosis changes dynamically during Drosophila retina development. Different cell types, like mitotic and postmitotic cells, employ unique survival strategies, impacting tissue development.
Area of Science:
- Developmental Biology
- Cell Biology
Background:
- Apoptosis mechanisms are understood, but regulation of cell susceptibility in developing tissues remains unclear.
- Developing tissues require precise control over cell survival and death.
Purpose of the Study:
- To investigate the dynamic changes in apoptosis susceptibility across different cell types in the developing Drosophila retina.
- To identify mechanisms cells use to modulate their survival during tissue development.
Main Methods:
- Analysis of apoptosis susceptibility in various Drosophila retinal cell types over a 24-hour period.
- Investigation of survival pathways involving Diap1 (inhibitor of apoptosis protein 1) and EGFR signaling.
Main Results:
- Mitotic cells show high susceptibility to apoptosis, while postmitotic cells develop survival strategies.
- Photoreceptor neurons initially accumulate Diap1 for survival; later, Diap1 degradation increases susceptibility.
- R8 photoreceptors exhibit robust survival mechanisms independent of EGFR or Diap1.
Conclusions:
- Cellular susceptibility to apoptosis is complexly regulated during organ development.
- Dynamic regulation of apoptosis likely occurs in mammalian development and could be exploited by tumors.
