2017 Fiscal Year Final Research Report
A novel formation of double-strand DNA breaks in the haploid germline nuclei of Tetrahymena thermophila. Study for its molecular mechanisms and biological roles
Project/Area Number |
15K18475
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Research Category |
Grant-in-Aid for Young Scientists (B)
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Allocation Type | Multi-year Fund |
Research Field |
Molecular biology
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Research Institution | Tohoku University |
Principal Investigator |
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Research Collaborator |
AKEMATSU Takahiko University of Vienna, Department of Chromosome Biology・Center for Molecular Biology, INDICAR Fellow
PEARLMAN E. Ronald York University, Dept. of Biology・Core Molecular Biology Facility, Director, University Professor Emeritus and Senior Scholar
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Project Period (FY) |
2015-04-01 – 2018-03-31
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Keywords | クロマチン再構築 / DSB / テトラヒメナ / 配偶核 |
Outline of Final Research Achievements |
In this study, molecular mechanisms and biological roles of a novel formation of post-meiotic DNA double-strand breaks (DSB) in the haploid micronuclei (pronuclei) of Tetrahymena thermophila were analyzed. After completion of meiosis, the TopII, and Spo11 mediated DSB formation in all the four pronuclei. Soon thereafter, DNA repair including histone replacement took place in the pronucleus that was adjacent to the mating-junction. This nucleus then began an additional mitosis as the selected pronucleus to produce gametic nuclei, while the other three unselected nuclei with persistent DSB eventually disappeared from the cytoplasm. Defective DSB formation in mutant strains abolishes not only nuclear selection but also histone replacement. These results suggest that the post-meiotic DSB is likely an intrinsic developmental program of the pronucleus and potentially contributes to chromatin remodeling to produce gametic nuclei capable of forming a zygotic nucleus.
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Free Research Field |
分子生物学
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