| Project/Area Number |
21790189
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | Jichi Medical University |
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Principal Investigator |
YAJIMA Hiroshi Jichi Medical University, 医学部, 講師 (10433583)
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| Project Period (FY) |
2009 – 2010
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| Project Status |
Completed (Fiscal Year 2010)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2010: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2009: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
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| Keywords | 発生 / 分化 / 神経堤細胞 / 脊髄神経節 / 感覚神経 / 一次知覚神経 / Six遺伝子 / 発生・分化 |
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| Research Abstract |
In the trunk of adult vertebrates, dorsal root ganglia (DRG) convey a variety of sensory modalities to the nervous system. However, during fish and amphibian development, intramedullary sensory neurons, Rohon-Beard (RB) cells, are responsible for juvenile mechanosensation and functionally substituted by DRG. In Xenopus RB cells, Six1 appears just before the switching. Forced expression of Six1 in Xenopus early embryo reduced the number of RB cells but induced premature extramedullary sensory neurogenesis. Genetic elimination of both Six1 and Six4 in mouse caused the emergence of RB-like cells within spinal cord. Since Six1 is expressed from the beginning of mouse DRG development, the heterochronic shift of the expressions of Six1 might be a key step in the evolution of vertebrate primary sensory system in the trunk.
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