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A β-glucuronidase (GUS) Based Cell Death Assay
Published on: May 6, 2011
Programmed cell death in Giardia.
Susmita Bagchi1, Abraham E Oniku, Kate Topping
1Davis Hall, Lehman College, CUNY, 250 Bedford Park Boulevard West, Bronx, NY10468, USA.
Parasitology
|March 13, 2012
Summary
Giardia exhibits unique programmed cell death (PCD) pathways. While lacking classical apoptosis genes, it shows autophagic changes and stress-induced morphological alterations, suggesting an early PCD form.
Area of Science:
- Cell Biology
- Eukaryotic Microbiology
- Evolutionary Biology
Background:
- Programmed cell death (PCD) is crucial in eukaryotes, but pathways are poorly understood in unicellular organisms.
- Giardia, an early-divergent amitochondrial eukaryote, has recently been implicated in PCD.
- Investigating PCD in Giardia offers insights into early eukaryotic cell death mechanisms.
Purpose of the Study:
- To investigate the mechanisms of programmed cell death (PCD) in Giardia.
- To identify genes associated with PCD, apoptosis, and autophagy in Giardia genomes.
- To characterize Giardia's cellular responses to stress and starvation.
Main Methods:
- Bioinformatic survey of Giardia genomes for PCD-related genes.
- Induction of morphological changes using oxidative stress (H2O2) and metronidazole.
- Detection of caspase activity and autophagic changes (MDC staining).
Main Results:
- No genes associated with classical apoptotic-like PCD were identified in Giardia genomes.
- Apoptotic-like morphological changes were induced by H2O2 and metronidazole, without caspase activity.
- Starvation induced autophagy-like changes, with key autophagy genes (TOR, ATG1, ATG16) identified.
Conclusions:
- Giardia possesses a unique form of apoptosis distinct from classical mechanisms.
- Giardia exhibits an autophagic pathway, supported by identified genes.
- These findings suggest Giardia may represent an early form of programmed cell death.
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