2004 Fiscal Year Final Research Report Summary
Molecular mechanisms of mitochondria-related ageing in Drosophila
| Project/Area Number |
15570004
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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 |
Genetics/Genome dynamics
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| Research Institution | Ochanomizu University |
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Principal Investigator |
MATSUURA E.T. Ochanomizu University, Department of Biology, Professor, 理学部, 教授 (00111691)
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| Co-Investigator(Kenkyū-buntansha) |
KONDO R. Ochanomizu University, Department of Biology, Assistant Professor, 理学部, 講師 (40293104)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Drosophila / ageing / mitochondria / mitochondrial DNA |
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| Research Abstract |
Mitochondrial dysfunction due to the accumulation of damage with age has been proposed to cause ageing. Previous studies have documented various changes related to mitochondria with age, however, results reported in Drosophila were not necessarily consistent with those from other animals. In the present study, changes in mitochondria with age, including the occurrence of deletions in mtDNA, the fine structure of mitochondria, and the respiratory function of mitochondria, were investigated in D.melanogaster. Further, longevity was examined in some strains of D.melanogaster in which mtDNA was replaced with that of its sibling species. The results are as follows.
(1)By PCR and Southern hybridization, the accumulation of deleted mtDNA was examined at various ages. The results showed that deleted mtDNA accumulated with age in a tissue-specific manner; deleted mtDNA was found more frequently in thorax as compared with head and abdomen. DNA sequencing determined the breakpoints of the deletion
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s, and most of the deletions were found to be flanked by short direct repeats.
(2)The observation of muscles in thoraces by electron microscopy showed that swollen mitochondria, which have been reported in aged individuals thus far, were already present at 35-day-old after which longevity decreased drastically. On the other hand, respiratory function was examined for the activities of the complex I and II, using mitochondria prepared from adult flies every ten days after eclosion. The results indicated that the activities gradually decreased right after eclosion.
(3)Longevities of D.melanogaster strains in which mtDNA was completely replaced by that of its sibling species were examined for three different strains. They possessed mtDNA derived from D.mauritiana(mal), D.mauritiana(mall), and D.simulans(siIII), respectively. The longevity of each strain significantly decreased at 28℃ as compared with its original strain. The determination of the DNA sequences of these mtDNA are in progress.
These results strongly suggest that mitochondria are involved in the process of ageing also in Drosophila, and confirm that Drosophila provides a useful model system for the study of ageing. The investigation in Drosophila, combined with that for nuclear genome, would contribute to the study of ageing. Less
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Research Products
(2 results)
