1989 Fiscal Year Final Research Report Summary
REGULATORY MECHANISMS OF GENE EXPRESSION IN DIFFERENTIATION OF SLIME MOLD CELLS
| Project/Area Number |
62440003
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物生理学
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| Research Institution | OKAZAKI NATIONAL RESEARCH INSTITUTES (1989)
Kyoto University (1987-1988) |
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Principal Investigator |
TAKEUCHI I. NATIONAL INSTITUTE FOR BASIC BIOLOGY, DIRECTOR-GENERAL, 基礎生物学研究所, 所長 (90025239)
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| Co-Investigator(Kenkyū-buntansha) |
OKAMATO K. KYOUTO UNIVERSITY, FACULTY OF SCIENCE ASSOCIATE PROFESSOR, 理学部, 助教授 (10029944)
TASAKA M. NATIONAL INSTITUTE FOR BASIC BIOLOGY, DIVISION OF DEVELOPMENTAL BIOLOGY, RESEARC, 基礎生物学研究所, 助手 (90179680)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Cell Differentiation / Gene expression / Pattern formation / Molecular biology / Collular slime mold |
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| Research Abstract |
1. When cells of the cellular slime mold aggregate to from a tissue, two types of cells (prespore and prestalk) differentiate. We obtained cDNA clones for mRNAs which are specifically accumulated in either cell type during the process of differentiation and examined developmental changes of their accumulation. It was found that some genes are expressed from the vegetative stage onward and the others after tissue formation. Determination of transcriptional activity of these genes with isolated nuclei revealed that the former genes are transcribed in both prespore and prestalk cells while the latter are only transcribed in either cell type. This indicates that cell-type-specific accumulation of mRNAs is controlled either by selective transcription or post-trancriptional degradation.
2. We cloned two genes specifically transcribed in prespore cells and revealed the whole structure. The cis-regulating elements in the 5'-upstream region of the genes were located by the use of transformation. The region coinejdod with the DNAse I-hypersensitive sites of a gene which were specifically found when the gene was expressed. Search for nueloar factors with bind with this region of a gene by the use of gel shift assay resulted in identification of three mucloar proteins.
3. Upon disaggregation of a tissue, the transcription of these presporo- specific genes was immediately suspended and the accumulated mRNAs were degraded. When exogenons cAMP was added to disaggregated cells, however, cAMP which was bound to the cell surface receptor directly induced the transcription of these genes through a signal transduction system within the cells. Furthermore, the mRNAs synthesized became stabilized by a protein(s) synthesized in the presence of cAMP.
4. We found that one of the mRNAs which are present from the vegetative stage onward encodes a polypetide elongation factor, EF2 of the slime mold. The gene was cloned and the whole structure identified.
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Research Products
(14 results)
