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Updated: Jun 1, 2026
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Dissection and Immunohistochemistry of Larval, Pupal and Adult Drosophila Retinas
Published on: November 14, 2012
Interlocked feedforward loops control cell-type-specific Rhodopsin expression in the Drosophila eye
Robert J Johnston1, Yoshiaki Otake, Pranidhi Sood
1Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA.
Cell
|June 14, 2011
Summary
Complex gene networks control cell development. In Drosophila eyes, the defective proventriculus (dve) gene acts as a key regulator, using opposing feedforward loops to precisely determine photoreceptor cell types.
Area of Science:
- Developmental biology
- Genetics
- Molecular biology
Background:
- Cell-type determination is crucial for development.
- Rhodopsin expression patterns define photoreceptor subtypes in the Drosophila eye.
- The regulatory networks governing this specificity are not fully understood.
Purpose of the Study:
- To investigate the role of the transcription factor gene defective proventriculus (dve) in regulating Rhodopsin expression.
- To elucidate the network architecture controlling cell-type determination in the Drosophila eye.
Main Methods:
- Analysis of gene regulatory networks involving transcription factors.
- Investigating feedforward loop (FFL) mechanisms.
- Studying gene expression patterns in Drosophila photoreceptors.
Main Results:
- Dve acts as a critical node in a network regulating Rhodopsin expression.
- An incoherent FFL involving Orthodenticle and Dve represses Rhodopsin expression.
- A coherent FFL in R7 and R8 photoreceptors relieves Dve-mediated repression and activates Rhodopsin expression.
- Dve levels are finely tuned for cell-type- and region-specific outcomes.
Conclusions:
- The regulatory network utilizes repression to restrict and combinatorial activation to induce cell-type-specific Rhodopsin expression.
- Interlocked FFLs represent a potential general mechanism for controlling terminal cell-fate specification.
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