| Project/Area Number |
05558096
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Neurochemistry/Neuropharmacology
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| Research Institution | Kumamoto University |
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Principal Investigator |
TANAKA Hideaki Division of Developmental Neurobiology, Kumamoto University, Graduate School of Medical Sciences, Professor, 医学部, 教授 (90106906)
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| Co-Investigator(Kenkyū-buntansha) |
OHTA Kunimasa Identical with the H.I., Research Associate School of Medicine, Kumamoto Univers, 医学部, 助手 (90244128)
IYAMA Kenichi Identical with the H.I., Assosiate Professor School of Medicine, Kumamoto Univer, 医学部, 助教授 (10040536)
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| Project Period (FY) |
1993 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥20,100,000 (Direct Cost: ¥20,100,000)
Fiscal Year 1995: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1994: ¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1993: ¥10,800,000 (Direct Cost: ¥10,800,000)
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| Keywords | cDNA cloning / Motoneuron / Receptor type tyrosine kinase / mRNA Differential Display / In situ hybridization / Neural network formation / ニワトリ胚脊髄 / Differentical Display / mRNA / Differential Display / nRNA / レセプター / チロシンキナーゼ / RT-PCR / In situ ハイブリダイゼーション |
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| Research Abstract |
Since neuronal cells have own characteristics from the beginning of their differentiation, the correct path finding to their correct target cells is essential for establishing neural network. Selective axonal growth is considered to be achieved by active interactions between the cues provided along the pathway and the recognition molecules localized on the growth cones. To identify such cues and recognition molecules, we focused on the chick embryonic lumbar motoneurons, because their axonal growth is analyzed in great detail and we can obtain enough materials from the embryos. We tried to identify molecules that are uniquely expressed on motoneurons or their subtypes from the cDNA libraries made from the purified embryonic day 5 (E5) chick motoneurons by panning, using antibody against SC1 that is uniquely expressed on motoneuron cell surface. We then performed RT-PCR for receptor tyrosine kinases (RTKs) and mRNA differential display. To date, RTKs comprise at least 16 subfamilies based upon their structural motifs. From enriched motoneurons, we identified 12 RTK subfamilies and found by in situ hybridization that Cek8, a member of Eph subfamily, is specifically expressed on motoneurons at the brachial and lumbar segments of the spinal cord which innervate limb muscles. Furthermore, Cek4 of the same family is expressed on motoneurons innervating axial muscles, whereas Ret RTK is expressed in all motoneurons. From the mRNA differential display we cloned nearly 40 cDNA clones and found at least 3 novel molecules are uniquely expressed on all or subpopulation of motoneurons. We are now analyzing the biological functions of Cek4, Cek8, Ret and the novel molecules expressed on the motoneurons.
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