Abstract
Photoreceptor neurons (R cells) in the Drosophila visual system elaborate a precise map of visual space in the brain. The eye contains some 750 identical modules called ommatidia, each containing eight photoreceptor cells (R1-R8). Cells R1-R6 synapse in the lamina; R7 and R8 extend through the lamina and terminate in the underlying medulla. In a screen for visual behavior mutants, we identified alleles of flamingo (fmi) that disrupt the precise maps elaborated by these neurons. These mutant R1-R6 neurons select spatially inappropriate targets in the lamina. During target selection, Flamingo protein is dynamically expressed in R1-R6 growth cones. Loss of fmi function in R cells also disrupts the local pattern of synaptic terminals in the medulla, and Flamingo is transiently expressed in R8 axons as they enter the target region. We propose that Flamingo-mediated interactions between R-cell growth cones within the target field regulate target selection.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alleles
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Animals
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Body Patterning / genetics
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Brain / growth & development*
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Brain / metabolism
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Brain / ultrastructure
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Brain Mapping
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Cadherins / genetics
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Cadherins / metabolism*
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Cell Adhesion / genetics
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Cell Communication / genetics
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Cell Differentiation / genetics*
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Drosophila Proteins
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Drosophila melanogaster / growth & development*
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Drosophila melanogaster / metabolism
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Drosophila melanogaster / ultrastructure
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Gene Expression Regulation, Developmental / genetics
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Growth Cones / metabolism*
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Growth Cones / ultrastructure
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Microscopy, Electron
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Mosaicism / genetics
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Mutation / genetics
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Photoreceptor Cells, Invertebrate / growth & development*
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Photoreceptor Cells, Invertebrate / metabolism
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Photoreceptor Cells, Invertebrate / ultrastructure
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Synapses / metabolism
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Synapses / ultrastructure
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Visual Pathways / growth & development*
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Visual Pathways / metabolism
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Visual Pathways / ultrastructure
Substances
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Cadherins
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Drosophila Proteins
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stan protein, Drosophila