Detection and processing of color in the Drosophila visual system
Claude Desplan (New York University)
Our laboratory focuses on two major developmental questions: The evolution of early embryonic development (which will not be discussed) and the establishment of retinal and brain circuitry that underlies color vision. Color vision is achieved through the comparison in the brain of inputs coming from photoreceptors containing photopigments (rhodopsins) with different wavelength specificity. Different rhodopsins are expressed in stochastic but mutually exclusive patterns in the compound eye of Drosophila as in cones of the vertebrate retina. This implies that there is a process for choosing a given rhodopsin gene and to transcriptionally repress all others. From this choice, another mechanism must then inform the brain of its connection to a photoreceptor with a specific color sensitivity. We use molecular and genetic approaches to identify most of the functions involved in the establishment of the retinal mosaic and the signaling pathways responsible for the elaboration of this sensory system. We are also imaging the target neurons of photoreceptors in the optic lobes and we are manipulating (ablation or silencing) these neurons to obtain a functional map the neural network underlying color vision. We have developed a color behavior assay to assay how changes in the retina or optic lobe neurons affect the visual process. We hope to understand how color vision has evolved and how brain processing allows the fly to detect its color environment.
Representative Publications 2006-2008 on color vision
- Sprecher, S.G., & Desplan C. Switch of rhodopsin expression in terminally differentiated Drosophila sensory neurons Nature 454, 533-537 (2008)
- Mazzoni, E, Celik, A., Wernet, M, Vasiliauskas, D., Cook, T, Johnston, R.J., Pichaud, F. & Desplan C. Iroquois-Complex genes induce co-expression of visual pigments in Drosophila. PLoS Biology 6, e97,825-835 (2008).
- Johnston R.J. Jr & Desplan C. Stochastic neuronal cell fate choices. Curr Opin Neurobiol. 18, 20-27 (2008)
- Yamaguchi, S., Wolf, R., Desplan C., & Heisenberg M. Motion vision is independent of color in Drosophila. Proc. Natl. Acad. Sci USA 105, 4910-4915 (2008)
- Morante J., & Desplan C. The color-vision circuit in the medulla of Drosophila.
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