2001 Fiscal Year Final Research Report Summary
Regulation of chromatin remodeling at meiotic recombination initiation sites
| Project/Area Number |
11680712
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Cell biology
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| Research Institution | The Institute of Physical and Chemical Research |
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Principal Investigator |
OHTA Kunihiro RIKEN, Genetic Dynamics Research Unit, Deputy Chief Research Scientist, 染色体動態制御研究ユニット, 副主任研究員 (90211789)
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| Project Period (FY) |
1999 – 2001
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| Keywords | recombination / hot spot / meiosis / fission yeast / chromatin / histone acetylation / SAPK / Mrell |
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| Research Abstract |
In eukaryotes, meiotic recombination initiation is initiated by transient meiosis-specific DNA double.strand breaks (DSBs) that occur at chromosomal sites called recombination hotspots. Recombination hotspots are often found in accessible chromosomal regions. Thus, chromatin structure plays pivotal roles in the regulation of meiotic recombination. In the present study, we investigated the molecular mechanisms on chromatin remodeling observed at the ade6-M26 recombination hotspot in fission yeast meiosis. We revealed that the stress-activated kinase cascade and the cAMP-dependent kinase (SAPK) pathways control the chromatin-remodeling at M26 counteractingly. The SAPK pathway activates the chromatin remodeling but PKA pathway operates oppositely. The M26 chromatin remodeling is also controlled by some genes responsible for meiotic induction. We found that the consensus sequence for the cAMP-responsive element (CRE) is required for the M26 hotspot activity and the chromatin remodeling. We discovered that natural CRE sites on fission yeast chromosome induce chromatin remodeling during early meiosis. Chromatin immunoprecipitation assay using anti-acetylated histone H3 and H4 revealed that M26 region is hyperacetylated in early meiosis. In addition, we found that histone acetylation by fission yeast Gcn5 histone acetyl transferase plays important roles in the regulation of chromatin remodeling, DSB formation, and recombination activation. Additional chromatin changes are induced by Rad32(the fission yeast Mrell homologue) and Rad50 recombination proteins. These results provide important clues to understand molecular basis of meiotic recombination activation.
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