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Updated: Mar 22, 2026
Imaging and Quantifying Mitochondrial Morphology in C. elegans During Aging
Published on: January 17, 2025
C. elegans miro-1 Mutation Reduces the Amount of Mitochondria and Extends Life Span
Yanqing Shen1, Li Fang Ng2, Natarie Pei Wen Low1
1Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Abstract:
Mitochondria play a critical role in aging, however, the underlying mechanism is not well understood. We found that a mutation disrupting the C. elegans homolog of Miro GTPase (miro-1) extends life span. This phenotype requires simultaneous loss of miro-1 from multiple tissues including muscles and neurons, and is dependent on daf-16/FOXO. Notably, the amount of mitochondria in the miro-1 mutant is reduced to approximately 50% of the wild-type. Despite this reduction, oxygen consumption is only weakly reduced, suggesting that mitochondria of miro-1 mutants are more active than wild-type mitochondria. The ROS damage is slightly reduced and the mitochondrial unfolded protein response pathway is weakly activated in miro-1 mutants. Unlike previously described long-lived mitochondrial electron transport chain mutants, miro-1 mutants have normal growth rate. These results suggest that the reduction in the amount of mitochondria can affect the life span of an organism through activation of stress pathways.
Insights
A mutation in the Miro GTPase (miro-1) gene extends lifespan in C. elegans by reducing mitochondria. This longevity requires DAF-16/FOXO and activates stress pathways.
Area of Science:
- Cell Biology
- Genetics
- Aging Research
Background:
- Mitochondria are crucial for aging, but mechanisms remain unclear.
- Mitochondrial dysfunction is linked to age-related decline.
- Understanding mitochondrial roles in aging is vital.
Purpose of the Study:
- To investigate the role of Miro GTPase (miro-1) in C. elegans aging.
- To elucidate the molecular mechanisms by which miro-1 affects lifespan.
- To explore the relationship between mitochondrial quantity and organismal healthspan.
Main Methods:
- Utilized genetic mutation in C. elegans to disrupt the miro-1 gene.
- Assessed lifespan, mitochondrial content, and oxygen consumption in miro-1 mutants.
- Investigated the dependence on DAF-16/FOXO and activation of stress response pathways.
Main Results:
- miro-1 mutants exhibited extended lifespan, dependent on DAF-16/FOXO.
- Mitochondrial content was reduced by ~50% in mutants, with only a minor decrease in oxygen consumption.
- Mutants showed slightly reduced ROS damage and weak activation of the mitochondrial unfolded protein response.
- Unlike other mitochondrial mutants, miro-1 mutants maintained a normal growth rate.
Conclusions:
- Reduced mitochondrial quantity, as seen in miro-1 mutants, can extend lifespan.
- This lifespan extension is mediated by the activation of stress response pathways.
- miro-1 disruption offers a novel pathway for understanding aging and mitochondrial regulation.
