| Project/Area Number |
61540492
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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 |
植物生理学
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| Research Institution | Osaka City University |
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Principal Investigator |
SHIMODA Chikashi Faculty of Science, Osaka City University, Associate Prof., 理学部, 助教授 (80047290)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1986: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Fission yeast / Meiosis / Sexual reproduction / Mating / Cloning / 遺伝子クローニング / ホメオボックス / 酵母 / 塩基配列決定 / ノザン法 / サザン法 |
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| Research Abstract |
Sexual reproduction of the fission yeast Schizosaccharomyces pombe is induced by the depletion of nigrogen sources. Genetic control systems operating during initiation of sexual reproduction (mating and meiosis) was investigated.
1. Studies on ste genes responsible for initiation of mating. A lot of sterile (mating-deficient) mutants of S. pombe were isolated and analysed. A nobel locus, ste11, was identified. Among eleven ste loci defined so far, seven genes including ste11 were found to be indispensable for the onset of meiosis in diploids. Furthermore, the ste1 mutant was defective in the normal entry into resting state in poor medium. However, this phenotype was due to the mutation of a novel gene, named trs1, but not to ste1 itself. The trs1 gene may regulate the entry of cells into the resting state.
2. Studies on the mie1 gene essential for initiation of meiosis. We have cloned the mei1 (mat2-Pi) gene and determined its nucleotide sequence. We found a possible open reading frame which may encode a polypeptide of 192 amino acid residues. Predicted amino acid sequences of the C-terminal region had a significant sequence homology with Sacch. cerevisiae MAT gene products and Drosophila homeodomains. Northern blot analysis with cloned mei1 gene as a probe revealed that the mei1 gene was transcribed to a 0.6 kb mRNA only under the condition of nitrogen starvation. We have also constructed a mei1-lacz fusion gene, and indicated that -galactiosidase activity was detected in S. pombe cells cultured in nitrogen source-free sporulation medium. This fusion gene will be useful for the molecular analysis of the mei1 promoter.
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