Related Experiment Video
Updated: May 30, 2026
08:43
Simultaneous Measurement of Mitochondrial Calcium and Mitochondrial Membrane Potential in Live Cells by Fluorescent Microscopy
Published on: January 24, 2017
Calcium-dependent mitochondrial extrusion in ciliated protozoa.
Yelena Bisharyan1, Theodore G Clark
1Department of Microbiology and Immunology, Veterinary Medical Center, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. ybisharyan@tetragenetics.com
Mitochondrion
|August 23, 2011
Summary
Ciliated protozoa can eject intact mitochondria to survive cellular stress. This process, triggered by surface antigen clustering or heat shock, involves calcium signaling and allows cells to recover.
Area of Science:
- Cell Biology
- Protozoology
- Organelle Biology
Background:
- Mitochondria are vital organelles responsible for cellular energy production.
- Extrusion of cellular components is a known stress response in some organisms.
- The specific mechanisms and triggers for mitochondrial expulsion in protozoa remain largely uncharacterized.
Purpose of the Study:
- To investigate the phenomenon of mitochondrial extrusion in ciliated protozoa.
- To identify the triggers and signaling pathways involved in this process.
- To explore the implications of mitochondrial discharge for cell survival and evolution.
Main Methods:
- Induction of mitochondrial extrusion via lateral clustering of GPI-anchored surface antigens and heat shock.
- Monitoring of intracellular calcium levels using fluorescent indicators.
- Pharmacological inhibition studies using Verapamil and BAPTA-AM.
- Assessment of cell viability post-mitochondrial discharge.
Main Results:
- Ciliated protozoa were observed to jettison intact mitochondria.
- Mitochondrial contents were released extracellularly, either soluble or within membrane vesicles.
- Extrusion was triggered by surface antigen clustering and heat shock.
- Calcium signaling, involving elevated intracellular calcium, was implicated in antigen-induced extrusion.
- Inhibition of calcium pathways (Verapamil, BAPTA-AM) blocked antigen-induced extrusion.
- Cells survived the process of mitochondrial discharge.
Conclusions:
- Ciliated protozoa possess a mechanism for actively expelling intact mitochondria.
- This extrusion is a stress response, potentially triggered by specific surface events or environmental changes.
- Calcium ions play a critical role in mediating antigen-induced mitochondrial discharge.
- Cellular survival following mitochondrial expulsion suggests an adaptive role, possibly an early evolutionary strategy for stress management.
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