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Division of Physarum mitochondria during starvation
Z Baranowski1, B Hrebenda, M Cieslawska
1Nencki Institute of Experimental Biology, Warszawa, Poland.
Cell Biology International Reports
|March 1, 1991
Summary
During starvation, Physarum polycephalum mitochondria synchronously divide, increasing their numbers while decreasing in size. This division coincides with altered mitochondrial structure and respiratory chain activity.
Area of Science:
- Cell Biology
- Biochemistry
- Mycology
Background:
- Physarum polycephalum is a model organism for studying cellular processes.
- Mitochondrial dynamics are crucial for cellular energy metabolism and adaptation.
- Starvation induces significant physiological changes in eukaryotic cells.
Purpose of the Study:
- To investigate the changes in mitochondrial morphology and number during starvation in Physarum polycephalum.
- To analyze the relationship between mitochondrial division and respiratory chain activity under stress.
- To characterize the structural alterations in newly formed mitochondria.
Main Methods:
- Stereological morphometry was used to quantify mitochondrial number and volume.
- Microplasmodia of Physarum polycephalum were subjected to controlled starvation.
- Mitochondrial ultrastructure and respiratory chain activity were assessed.
Main Results:
- Mitochondrial number per unit volume increased significantly (from 12 to 24 million) between hours 2 and 5 of starvation.
- Mean mitochondrial volume decreased (from 4.6 to 3.0 µm³) indicating synchronous division.
- Newly formed mitochondria exhibited denser matrix and less condensed cristae, alongside decreased respiratory chain activity and peak cyanide resistance.
Conclusions:
- Mitochondrial division in Physarum polycephalum is a synchronous process triggered by starvation.
- Starvation induces coordinated changes in mitochondrial biogenesis, structure, and metabolic function.
- These findings provide insights into cellular adaptation mechanisms under nutrient deprivation.
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