R7 Photoreceptor Specification in the Developing Drosophila Eye: The Role of the Transcription Factor Deadpan

Autor: Andrew Tomlinson, Yannis Emmanuel Mavromatakis
Rok vydání: 2016
Předmět:
0301 basic medicine
Photoreceptors
Cancer Research
Sensory Receptors
Transcription
Genetic
Cell
Social Sciences
Gene Expression
Biochemistry
Transcription (biology)
Animal Cells
Transcriptional regulation
Basic Helix-Loop-Helix Transcription Factors
Medicine and Health Sciences
Drosophila Proteins
Psychology
Transgenes
Genetics (clinical)
Genetics
Neurons
Staining
Receptors
Notch
Gene Expression Regulation
Developmental
Nuclear Proteins
Cell Staining
Cell biology
DNA-Binding Proteins
medicine.anatomical_structure
Drosophila melanogaster
Photoreceptor Cells
Invertebrate
RNA Interference
Sensory Perception
Cellular Types
Anatomy
Research Article
Signal Transduction
lcsh:QH426-470
Precursor Cells
DNA transcription
Protein degradation
Cell fate determination
Biology
Research and Analysis Methods
03 medical and health sciences
Ocular System
Precursor cell
medicine
Gene silencing
Animals
Cell Lineage
Gene Regulation
Molecular Biology Techniques
Transcription factor
Molecular Biology
Ecology
Evolution
Behavior and Systematics
Crosses
Genetic
Biology and Life Sciences
Afferent Neurons
Proteins
Cell Biology
Regulatory Proteins
Repressor Proteins
lcsh:Genetics
030104 developmental biology
Gene Expression Regulation
Specimen Preparation and Treatment
Cellular Neuroscience
Eyes
Gene Function
Head
Neuroscience
Transcription Factors
Cloning
Zdroj: PLoS Genetics
PLoS Genetics, Vol 12, Iss 7, p e1006159 (2016)
ISSN: 1553-7404
Popis: As cells proceed along their developmental pathways they make a series of sequential cell fate decisions. Each of those decisions needs to be made in a robust manner so there is no ambiguity in the state of the cell as it proceeds to the next stage. Here we examine the decision made by the Drosophila R7 precursor cell to become a photoreceptor and ask how the robustness of that decision is achieved. The transcription factor Tramtrack (Ttk) inhibits photoreceptor assignment, and previous studies found that the RTK-induced degradation of Ttk was critically required for R7 specification. Here we find that the transcription factor Deadpan (Dpn) is also required; it is needed to silence ttk transcription, and only when Ttk protein degradation and transcriptional silencing occur together is the photoreceptor fate robustly achieved. Dpn expression needs to be tightly restricted to R7 precursors, and we describe the role played by Ttk in repressing dpn transcription. Thus, Dpn and Ttk act as mutually repressive transcription factors, with Dpn acting to ensure that Ttk is effectively removed from R7, and Ttk acting to prevent Dpn expression in other cells. Furthermore, we find that N activity is required to promote dpn transcription, and only in R7 precursors does the removal of Ttk coincide with high N activity, and only in this cell does Dpn expression result.
Author Summary Animals are made from a vast diversity of different cell types, and understanding how they are specified is a major goal of developmental biology. In this study we use the Drosophila R7 photoreceptor as a model system for understanding how cell fate specification occurs. We examine the step when the R7 precursor cell adopts the photoreceptor fate, and ask how the signaling pathways active in the cell are integrated to provide an unambiguous directive to become a photoreceptor. The transcription factor Tramtrack (Ttk) represses the ability of the cell to become a photoreceptor, and how it is removed is the focus of this study. Previous work identified a protein degradation mechanism, and here we describe the role of the transcription factor Deadpan (Dpn) in repressing ttk transcription. We find that both the protein degradation mechanism and transcriptional silencing are required for efficient Ttk removal. Dpn expression needs to be restricted to the R7 precursor and we describe how the mutual antagonism between Ttk and Dpn and the action of the Notch signaling pathway are integrated to ensure that Dpn is selectively expressed in the cell.
Databáze: OpenAIRE
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