Mechanism of chromosome instability in fission yeast aneuploids
| Project/Area Number |
16370083
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Molecular biology
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| Research Institution | Kazusa DNA Research Institute |
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Principal Investigator |
NIWA Osami Kazusa DNA Research Institute, Group head, 染色体機能領域研究室, 室長 (70144318)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥15,400,000 (Direct Cost: ¥15,400,000)
Fiscal Year 2006: ¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2005: ¥6,800,000 (Direct Cost: ¥6,800,000)
Fiscal Year 2004: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Keywords | Aneuploid / Fission yeast / Cell division / Chromosome aberration / Polyploid / 3倍体 / ゲノム再編成 / 減数分裂 / 環境ストレス / 染色体分配 |
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| Research Abstract |
In many organisms, like plants and yeasts where polyploidy is common, the generation of aneuploids is inevitable ; that is, it occurs without erroneous chromosome transmission. Hence, there may be unknown mechanisms that eliminate aneuploids from the population. Findings from our previous genetic study suggested that at least some types of aneuploids in fission yeast can eventually survive as diploids or haploids after a period of anomalous growth during which unbalanced chromosome compositions must be corrected. In this study, we reexamined this issue to elucidate the mechanisms underlying aneuploid instability.
We first demonstrated that aneuploids between n and 2n were produced from triploid meioses at the expected ratio ; i.e., 75% of the meiotic segregants were aneuploid. Fluorescence microscopy of living cells revealed that abnormal or uneven nuclear divisions occurred in microcolonies from a portion of apparently aneuploid spores. In some cases, haploid or diploid cells emerged from microcolonies that also contained many dying cells.
Genetically defined diploid spores did not have such abnormalities. We suggest that anomalous nuclear divisions occurring in aneuploid cells might, on one hand, lead to the amplification of aneuploidy to enhance cell death, and, on the other hand, lead to the resolution of aneuploids into stable euploids. Further, we found that in some derivatives from a strain with chromosome 3 disomy, terminal deletion in either left arm or right arm of the chromosome was frequently recovered. This suggested that in fission yeast aneuploid cells, chromosomal breakage might be induced, so that it would lead to cell cycle arrest as well as to chromosome instability.
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Report
(4 results)
Research Products
(6 results)
