| Project/Area Number |
13640614
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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 |
遺伝
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| Research Institution | Kyoto Institute of Technology |
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Principal Investigator |
H.INOUE Yoshihiro Drosophila Genetic Resource Center, Lecturer, ショウジョウバエ遺伝資源センター, 講師 (90201938)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAGUCHI Masamitsu Faculty of textile science, Department of applied biology, Professor, 繊維学部, 教授 (00182460)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2002: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2001: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Mitosis / Chromosome / heterochromatin / Drosophila / ショジョウバエ / 染色体の異数化 |
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| Research Abstract |
A novel mitotic mutant, mtr^2, which had been isolated from our large-scale screens of Drosophila mitotic mutants, showed a high proportion of mitotic cells containing hyper-condensed chromatids that have undergone anaphase separation but that the segregation was prevented. Cytological examination of cells in the larval central nervous system from mtr^2 revealed that chromosome fragmentation occurred frequently at centromeres in the mutant cells. The mtr^2 cells contained abnormal mitotic spindles consisted of a less number of spindle microtubules. In the mtr^2 cells, chromatid separation can occur before metaphase even though they have the spindle defects. The abnormal anaphase-like cells in mtr^2 contained a comparable level of cyclin B to the normal level in metaphase cells. On the base or these cytological observations, we proposed a model that the primary defect or the mtr^2 is a perturbation of centromer structure and that it possibly leads to a loss of sister chromatid connection at centromere and further results in a failure of release from an active state of mitotic checkpoint after a completion of mitotic spindle formation. Genetic analyses of the mtr^2 revealed that the chromosome contains two separate mitotic mutations, a novel lethal mutation l(3)acc6487 and a female and male sterile mutation mtr^2. The mitotic phenotypes concerned with construction of centromeres corresponded with the l(3)acc6487 mutation. On the other hand, the mtr gene is required for a negative regulation of meiotic entry in Drosophila males. The mtr gene was localized to 98C region on the polytene chromosome and cloned the genomic region including this gene by a plasmid rescue. The mtr gene corresponds to the known gene, dlarp encoding a of the Lupas Antigen-related protein. A fine chromosome mapping for gene cloning of the l(3)acc6487 is now underway.
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