Abstract
During the final stages of Drosophila melanogaster oogenesis fifteen nurse cells, sister cells to the oocyte, degenerate as part of normal development. This process involves at least two cell death mechanisms, caspase-dependent cell death and autophagy, as indicated by apoptosis and autophagy markers. In addition, mutations affecting either caspases or autophagy partially reduce nurse cell removal, leaving behind end-stage egg chambers with persisting nurse cell nuclei. To determine whether apoptosis and autophagy work in parallel to degrade and remove these cells as is the case with salivary glands during pupariation, we generated mutants doubly affecting caspases and autophagy. We found no significant increase in either the number of late stage egg chambers containing persisting nuclei or in the number of persisting nuclei per egg chamber in the double mutants compared to single mutants. These findings suggest that there is another cell death mechanism functioning in the ovary to remove all nurse cell remnants from late stage egg chambers.
Highlights
Programmed cell death (PCD) is a conserved mechanism for eliminating excess cells during development and for maintaining homeostasis within an organism by removing unnecessary or unhealthy cells
The late stage oogenesis phenotypes observed in autophagy and apoptosis mutants were mild with respect to persisting nurse cell nuclei
If apoptosis and autophagy were working redundantly to remove nurse cells we would expect to see a synergistic effect with a large increase both in the number of egg chambers containing persisting nuclei (PN) as well as an increase in the number of PN per egg chamber
Summary
Programmed cell death (PCD) is a conserved mechanism for eliminating excess cells during development and for maintaining homeostasis within an organism by removing unnecessary or unhealthy cells. PCD in the Drosophila ovary occurs by unusual mechanisms, making it a powerful model for alternative forms of cell death. The Drosophila ovary is made up of hundreds of developing egg chambers that are contained in tubular structures called ovarioles. Each egg chamber begins formation at the anterior tip of the ovariole when one germline-derived cell, produced by asymmetric cell division from a stem cell, divides four times to form a cyst containing one oocyte and fifteen nurse cells. Somatic follicle cells surround the germline cyst to form the outer epithelial cell layer of the egg chamber [1]. As development proceeds through 14 distinct stages, the oocyte, fed by the nurse cells, increases in size, and becomes enclosed by the chorion, or eggshell, which is produced by the follicle cells [2]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
