2004 Fiscal Year Final Research Report Summary
Studies on developmental mechanisms of the Drosophila visual center
| Project/Area Number |
15370093
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Developmental biology
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
TABATA Tetsuya The University of Tokyo, Institute of Molecular and Cellular Biosciences, Professor, 分子細胞生物学研究所, 教授 (10183865)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Makoto The University of Tokyo, Institute of and Molecular Cellular Biosciences, Research associate, 助手 (30345235)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Drosophila / visual center / R axon / lamina neuron / Dpp / DWnt4 / Hedgehog / Sim |
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| Research Abstract |
In Drosophila, photoreceptor cells topographically send their axons to the first optic ganglion, the lamina. 1.dpp is expressed at the margin of the lamina target region, where glial precursors reside. Inhibition of DPP signaling in this region resulted in defects in the differentiation of the lamina glial cells. Expression of glial cells missing (gcm) depends on DPP. In addition, R axon projections and lamina glia development were impaired by the expression of a dominant-negative form of gcm, suggesting that gcm controls the differentiation of lamina glial cells. These results suggest that DPP signaling mediates the maturation of the lamina glia required for the correct R axon projection pattern by controlling the expression of gcm. 2.R axons trigger proliferation and differentiation of lamina neurons by delivering the inductive signal, Hedgehog(Hh). We found that the bHLH-PAS transcription factor Single-minded (Sim) is induced by Hh in the lamina neurons and is required for the association of lamina neurons with R axons. In sim mutant brains, lamina neurons fail to associate with R axons. As a result, lamina neurons are set aside from R axons. The data reveal a novel mechanism for regulation of the interaction between axons and neuronal cell bodies that establishes precise neuronal networks. 3. In DWnt4 mutants, ventral retinal axons misprojected to the dorsal lamina. DWnt4 is normally expressed in the ventral half of the developing lamina and DWnt4 protein was detected along ventral retinal axons. Dfrizzled2 and dishevelled, respectively, encode a receptor and a signaling molecule required for Wnt signaling. Mutations in both genes caused DWnt4-like defects, and were autonomously required in the retina, suggesting direct roles of DWnt4 for retinal axon guidance. In contrast, iroquois homeobox genes are the dorsal cues for the retina.
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Research Products
(6 results)
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[Journal Article] DPP signaling controls development of the lamina glia required for retinal axon targeting in the visual system of Drosophila.2005
Author(s)
Yoshida, S., Soustelle, L., Giangrande, A., Umetsu, D., Murakami, S., Yasugi, T., Awasaki, T., Ito, K., Sato, M., Tabata, T.
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Journal Title
Development 132・20
Pages: 4587-4598
Description
「研究成果報告書概要(和文)」より
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[Journal Article] DPP signaling controls development of the lamina glia required for retinal axon targeting in the visual system of Drosophila.2005
Author(s)
Yoshida, S., Soustelle, L., Giangrande, A., Umetsu, D., Murakami, S., Yasugi, T., Awasaki, T., Ito, K., Sato, M., Tabata, T.
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Journal Title
Development 132 (20)
Pages: 4587-4598
Description
「研究成果報告書概要(欧文)」より
