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Updated: Jun 2, 2026
Studying Mitochondrial Structure and Function in Drosophila Ovaries
Published on: January 4, 2017
Reversible response of protein localization and microtubule organization to nutrient stress during Drosophila early
Yuko Shimada1, K Mahala Burn, Ryusuke Niwa
1Department of Genetics, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
Abstract:
The maturation of animal oocytes is highly sensitive to nutrient availability. During Drosophila oogenesis, a prominent metabolic checkpoint occurs at the onset of yolk uptake (vitellogenesis): under nutrient stress, egg chambers degenerate by apoptosis. To investigate additional responses to nutrient deprivation, we studied the intercellular transport of cytoplasmic components between nurse cells and the oocyte during previtellogenic stages. Using GFP protein-traps, we showed that Ypsilon Schachtel (Yps), a putative RNA binding protein, moved into the oocyte by both microtubule (MT)-dependent and -independent mechanisms, and was retained in the oocyte in a MT-dependent manner. These data suggest that oocyte enrichment is accomplished by a combination of MT-dependent polarized transport and MT-independent flow coupled with MT-dependent trapping within the oocyte. Under nutrient stress, Yps and other components of the oskar ribonucleoprotein complex accumulated in large processing bodies in nurse cells, accompanied by MT reorganization. This response was detected as early as 2h after starvation, suggesting that young egg chambers rapidly respond to nutrient stress. Moreover, both Yps aggregation and MT reorganization were reversed with re-feeding of females or the addition of exogenous insulin to cultured egg chambers. Our results suggest that egg chambers rapidly mount a stress response by altering intercellular transport upon starvation. This response implies a mechanism for preserving young egg chambers so that egg production can rapidly resume when nutrient availability improves.
Insights
Drosophila egg chambers rapidly alter intercellular transport under nutrient stress, accumulating specific proteins in nurse cells. This stress response is reversible with nutrient re-supply or insulin, preserving egg chambers for future development.
Area of Science:
- Developmental Biology
- Cell Biology
- Molecular Biology
Background:
- Oocyte maturation is sensitive to nutrient availability, with nutrient stress triggering apoptosis in Drosophila egg chambers.
- Understanding cellular responses beyond apoptosis is crucial for comprehending oogenesis under stress.
Purpose of the Study:
- To investigate the intercellular transport of cytoplasmic components during previtellogenic stages in Drosophila oogenesis.
- To identify responses to nutrient deprivation beyond egg chamber apoptosis.
Main Methods:
- Utilized GFP protein-traps to track the movement of Ypsilon Schachtel (Yps) and other ribonucleoprotein complex components.
- Observed microtubule (MT) dynamics and reorganization in nurse cells during nutrient stress.
- Examined the effects of re-feeding and exogenous insulin on Yps aggregation and MT organization.
Main Results:
- Ypsilon Schachtel (Yps) is transported into the oocyte via microtubule (MT)-dependent and -independent pathways and retained in an MT-dependent manner.
- Under nutrient stress, Yps and oskar ribonucleoprotein complex components aggregate in nurse cell processing bodies, accompanied by MT reorganization.
- These stress responses are rapidly initiated (within 2 hours of starvation) and are reversible upon nutrient re-supply or insulin treatment.
Conclusions:
- Drosophila egg chambers exhibit a rapid stress response to nutrient deprivation by altering intercellular transport mechanisms.
- This response involves the aggregation of key proteins and MT reorganization in nurse cells, suggesting a mechanism to preserve developing oocytes.
- The reversibility of this response highlights a strategy for rapid resumption of egg production when nutrient conditions improve.
