The study on the locus regulating the cell polarity in axenic strains of the cellular slime mold
Project/Area Number |
02804060
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
植物形態・分類学
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Research Institution | The Tokyo Metropolitan Institute of Medical Science |
Principal Investigator |
SAMESHIMA Masazumi The Tokyo Metropolitan Institute of Medical Science, Department of Ultrastructural Research, Researcher, 超微形態研究部門, 研究員 (90142653)
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Project Period (FY) |
1990 – 1992
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Project Status |
Completed (Fiscal Year 1992)
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Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1992: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥1,500,000 (Direct Cost: ¥1,500,000)
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Keywords | Cell polarity / Microtubules / nucleus / Dictyostelium discoideum / Axenic mutation / Electron microscope / Indirect immunofluorescence / Axneic mutation / 間接蛍光抗体法 / Dictyostelium / MAPs / 細胞性粘菌 / 微小管形成中心 |
Research Abstract |
The nucleus and the microtubule-organizing center (MTOC) are though to define major cell polarity with respect to an apical-basal or anterior-posterior axis of cells. Positioning of the MTOC in aggregating Dictyostelium discoideum was found to be genetically regulated. 1. All wild-type strains examined showed similar cell polarity, as defined by the alignment of the nucleus in advance of the MTOC. 2. On the contrary, in Ax2 and Ax3, axenic strains carrying axenic mutations on linkage groups II and III, the MTOC was located ahead of the nucleus. 3. Cells containing axenic linkage group II but not III positioned the MTOC ahead of the nucleus. Conversely strains having axenic linkage group III but not II positioned it posterior to the nucleus. Thus the axenic linkage group II is responsible for the location of the MTOC anterior to the nucleus. 4. Three recessive mutations, axeC, oaaA and daxA, are assigned to axenic linkage group II in Ax3. However, phenotypes of oaaA and daxA did not correlate with anterior position of the MTOC. Therefore, axeC may have pleiotropic effects on axenic growth and MTOC positioning, or other linked gene(s) not yet identified may be responsible for anterior positioning of the MTOCs. 6. Wild-type NC-4 cells probably have a basal machinery regulating the position of the MTOC either behind or ahead of the nucleus. Gene(s) in link-age group II may mutate in axenic strains in order to stimulate anterior position or to prevent posterior positioning of the MTOCs. 7. When microtubule-related proteins were analyzed on SDS-PAGE stained with CBB, bands at 116 and 170-190 kd increased in the strain positioning the MTOC anterior to the nucleus compared with those in NC-4.
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Report
(4 results)
Research Products
(9 results)