1987 Fiscal Year Final Research Report Summary
Molecular Basis of the Mechanism Involved in the Modification of Differentiation Pattern of Dictyostelium by Low Temperature
| Project/Area Number |
61540504
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物形態・分類学
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| Research Institution | Osaka University |
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Principal Investigator |
MAESA MINEKO Dept. Biol., College of Gen. Educ., Osaka Univ., 教養部, 助手 (70029700)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Dictyostelium / prespore cells / prespore vesicles / cyclic AMP / cyclic nucleotides / spore-specific antigens / cytoskeleton |
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| Research Abstract |
When dictyostelium cells at either the late aggregation or migrating slug stage were incubated under low temperature conditions, they did not form fruiting bodies but globular structures in which majority of cells differentiated into spores. The fact demonstrates that prespore-specific vesicles (PSVs) can be produced and stabilized even under an extremely low temperature condition. To elucidate the mechanism PSV-formation and stabilization under the condition, following experiments were conducted.
1. Identification of spore-specific antigens: It was found by immunoblotting that major species of spore-specific antigens were 200kD, 140kD, 116kD, 96kD, 80kD, 70kD, 60kD, 40kD and 16kD. The accumulation of the antigens in PSVs proceeded in two steps, while the destruction of them began at the same time in the course of dedifferentiation.
2. Effects of cAMP and its analogs on the stability of PSVs: Cyclic AMP higher than 10^<-5> M as well as 2 -deoxy cAMP and 8-bromo cAMP stabilized PSVs irrespective of cell density.
3. Relationship among PSV-stability, lysosomes and cytoskeletons: Lysosomal inhibitors like chloroquine and NH_4Cl stabilized PSVs and a microtubule-blocker (ethylphenyl carbamate) did it.
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