Relationship between mitochondrial electron transport chain dysfunction, development, and life extension in Caenorhabditis elegans.

Shane L. Rea, Natascia Ventura, Thomas E. Johnson

Research output: Contribution to journalArticle

217 Citations (Scopus)

Abstract

Prior studies have shown that disruption of mitochondrial electron transport chain (ETC) function in the nematode Caenorhabditis elegans can result in life extension. Counter to these findings, many mutations that disrupt ETC function in humans are known to be pathologically life-shortening. In this study, we have undertaken the first formal investigation of the role of partial mitochondrial ETC inhibition and its contribution to the life-extension phenotype of C. elegans. We have developed a novel RNA interference (RNAi) dilution strategy to incrementally reduce the expression level of five genes encoding mitochondrial proteins in C. elegans: atp-3, nuo-2, isp-1, cco-1, and frataxin (frh-1). We observed that each RNAi treatment led to marked alterations in multiple ETC components. Using this dilution technique, we observed a consistent, three-phase lifespan response to increasingly greater inhibition by RNAi: at low levels of inhibition, there was no response, then as inhibition increased, lifespan responded by monotonically lengthening. Finally, at the highest levels of RNAi inhibition, lifespan began to shorten. Indirect measurements of whole-animal oxidative stress showed no correlation with life extension. Instead, larval development, fertility, and adult size all became coordinately affected at the same point at which lifespan began to increase. We show that a specific signal, initiated during the L3/L4 larval stage of development, is sufficient for initiating mitochondrial dysfunction-dependent life extension in C. elegans. This stage of development is characterized by the last somatic cell divisions normally undertaken by C. elegans and also by massive mitochondrial DNA expansion. The coordinate effects of mitochondrial dysfunction on several cell cycle-dependent phenotypes, coupled with recent findings directly linking cell cycle progression with mitochondrial activity in C. elegans, lead us to propose that cell cycle checkpoint control plays a key role in specifying longevity of mitochondrial mutants.

Original languageEnglish (US)
JournalPLoS Biology
Volume5
Issue number10
DOIs
StatePublished - Oct 2 2007

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Caenorhabditis elegans
electron transport chain
Electron Transport
Life Expectancy
RNA Interference
Cells
RNA
RNA interference
Dilution
Cell Cycle Checkpoints
Cell Cycle
Gene encoding
Oxidative stress
cell cycle
Mitochondrial Proteins
Phenotype
Indicator Dilution Techniques
Mitochondrial DNA
phenotype
Protein C

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)

Cite this

Relationship between mitochondrial electron transport chain dysfunction, development, and life extension in Caenorhabditis elegans. / Rea, Shane L.; Ventura, Natascia; Johnson, Thomas E.

In: PLoS Biology, Vol. 5, No. 10, 02.10.2007.

Research output: Contribution to journalArticle

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