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Live-imaging of the Drosophila Pupal Eye
Published on: January 12, 2015
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Parsimony and complexity: Cell fate assignment in the developing Drosophila eye
Yannis Emmanuel Mavromatakis1, Andrew Tomlinson1
1a Department of Genetics and Development, College of Physicians and Surgeons , Columbia University , New York , NY , USA.
Fly
|February 7, 2017
Summary
Drosophila R7 photoreceptor development relies on a simple molecular code involving Tramtrack (Ttk) degradation and Notch (N) pathway activity. Complex interactions between RTK and N pathways refine cell fate decisions, with Lozenge (Lz) influencing outcomes.
Area of Science:
- Developmental Biology
- Cell Signaling
- Neuroscience
Background:
- The specification of the R7 photoreceptor in Drosophila serves as a model for cell fate determination.
- R7 photoreceptors, R1/6 photoreceptors, and cone cells arise from a common precursor pool.
- Receptor Tyrosine Kinase (RTK) and Notch (N) signaling pathways are crucial for directing these cell fates.
Purpose of the Study:
- To investigate the signals and cellular information governing R7, R1/6, and cone cell fate specification.
- To elucidate the molecular mechanisms underlying the crosstalk between RTK and Notch signaling pathways.
- To describe the role of transcription factor Lozenge (Lz) in retinal precursor fate determination.
Main Methods:
- Analysis of RTK and Notch signaling pathways in Drosophila eye development.
- Examination of the role of transcription factor Tramtrack (Ttk) in photoreceptor fate repression.
- Investigation of the combinatorial effects of Ttk degradation, N activity levels, and Lz presence on cell fate outcomes.
Main Results:
- Cell fate is determined by a binary code: Ttk degradation status and N activity level (high or low).
- RTK signaling promotes photoreceptor fate by degrading Ttk; absence of RTK signal leads to cone cell fate.
- High N activity with Ttk degradation specifies R7, while low N activity specifies R1/6 photoreceptors.
- Complex crosstalk between RTK and N pathways refines R7 fate specification, with Lz modulating cell type outcomes.
Conclusions:
- A simple molecular code of Ttk degradation and N activity levels underlies R7 photoreceptor specification.
- Intricate RTK-N pathway interactions and the presence of Lz contribute to the precise determination of retinal cell types.
- Understanding these pathways provides insights into fundamental principles of cell fate determination in developing systems.
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