| Project/Area Number |
07458197
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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 | National Institute for Basic Biology (NIBB), Okazaki National Research Institutes |
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Principal Investigator |
EGUCHI Goro NIBB,Department of Developmental Biology, Professor, 基礎生物学研究所, 教授 (80022581)
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| Co-Investigator(Kenkyū-buntansha) |
KOSAKA Mitsuko NIBB,Department of Developmental Biology, Research Associate, 基礎生物学研究所, 助手 (50270476)
MOCHII Makoto NIBB,Department of Developmental Biology, Research Associate, 基礎生物学研究所, 助手 (90202358)
KODAMA Ryuji NIBB,Department of Developmental Biology, Associate Professor, 基礎生物学研究所, 助教授 (90161950)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥7,100,000 (Direct Cost: ¥7,100,000)
Fiscal Year 1996: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1995: ¥4,200,000 (Direct Cost: ¥4,200,000)
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| Keywords | Dedifferentiation / Transdifferentiation / Stabilization in differentiation / Pigmented epithelial call / Growth factor / Homebox gene / Gene expression / 再生 / 細胞外基質 / 増殖因子 / 分化制御因子 / 脊椎動物 |
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| Research Abstract |
The following results were obtained by conducting the research plans in 1996.
(1) Through extensive studies to improve our authentic in vitro transdifferentiation system of retinal pigmented epithelial cells (PECs) from 8 to 10-day-old chick embryos, both bFGF were found to be essential factors regulating transdifferentiation of PECs. In addition, by introducing these tow growth factors to cell cultures, we succeeded in establishing a novel and highly stable in vitro experimental system of the iris PECs from neuwly-hatched chicks. The system allows us to manipulate the whole process of the lens transdifferentiation of PECs without any artificial reagent.
(2) Analyzes using this system revealed that activation of MAP kinase is an essential requisite for dedif-ferentiation of PECs and that the expression of two homeobox genes, pax6 and six3 are dramatically enhanced by coordinated functions of bFGF and EGF.
(3) The following results were obtained through detailed analysis of changes in the extracellular matrix (ECM) during transdifferentiation of PECs that beta1 integrin plays an essential role in stable maintenance of the differentiated state of PECs by transmitting signals from ECM components to PECs, and that beta1 integrin molecules are readily phospholylated to lose their function when dedifferentiation of PECs is initiated.
(4) It was resulted in by cloning and structural and functional analysis of avian microphthalmia gene (mi) that mutation of mi must be responsible for ectopic formation of the neural retina from the developing pigmented epithelium in Silver mutant of the quail, and also that mi is one of essential genes, which regulate dedifferentiation and transdifferentiation of the vertebrate PEC.
(5) These findings must provide the fundamental information required for approaching to the molecular mechanisms involved in transdifferentiation and stability in differentiation of tissue cells in general.
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