| Project/Area Number |
18500266
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nerve anatomy/Neuropathology
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| Research Institution | Fukushima Medical University |
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Principal Investigator |
YAGINUMA Hiroyuki Fukushima Medical University, School of Medicine, Professor (90230193)
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| Co-Investigator(Kenkyū-buntansha) |
HOMMA Shunsaku Fukushima Medical University, School of Medicine, Associate professor (20261795)
MASUDA Tomoyuki Fukushima Medical University, School of Medicine, Assistant professor (70372828)
佐藤 昇 福島県立医科大学, 医学部, 講師 (00254756)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,890,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥390,000)
Fiscal Year 2007: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2006: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | programmed cell death / LIM homeodomoain / transcription factor / cervical / motoneuron / Hox / development / avian / 運動神経細胞 / アポトーシス / 鳥類 / 哺乳類 / 頸髄 / レーザーダイセクション法 / 細胞死 / ニワトリ胚 / マウス胎仔 / BH3 only protein / Bcl2ファミリー |
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| Research Abstract |
To determine the identity of the dying motoneurons (MNs) undergoing programmed cell death (PCD) at relatively early stages (E4-E5 in the chick embryo) and only in the non-limb innervating cervical spinal cord, we examined expression of subgroup-specific MN markers (Isl1, Is12, Lim3, MNR2 and Foxpl) in the dying MNs. PCD occurs only in a subgroup of MNs that express Isl1, Isl2, MNR2 and FoxPl but that lack Lim3 expression. This Lim3-negative (Lim3) MN subgroup appears as a distinct subpopulation in the dorsolateral region of the ventral horn by E4 after losing Lim3 expression and they are no longer observed by E5. However, following the rescue of MNs by Bc12 overexpression, Lim3- persisted at least until E5-5.5. When Lim3 was overexpressed on one side of the spinal cord, the number of dying MNs was markedly decreased at E4.5 and the number of surviving healthy MNs was increased after the period of cell death (E5.5). These results suggest that the downregulation of Lim3 is involved in the specification of the cell death fate of early dying cervical MNs. Furthermore, the fact that Foxpl is expressed by dying MNs suggests that Hox proteins that are specific to the cervical segments may play a role in this type of cell death. In situ hybridizaiton for Hox genes revealed that Hoxc5, Hoxa3, Hoxa5 are expressed by cervical motoneurons and their rostro-caudal extents of expression cover the segments where early motoneuron death occurs. These Hox genes might be involved in the determination of motoneuron subgroups that under go cell death.
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