Eukaryotic Cell doi:10.1128/EC.00160-08
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
Anoxia-induced suspended animation in budding yeast as an experimental paradigm for studying oxygen-regulated gene expression
Kin Chan
and
Mark B. Roth*
Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195; Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
* To whom correspondence should be addressed. Email:
mroth{at}fhcrc.org.
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Abstract |
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Oxygen lack of various severity can force many organisms to enter into recoverable hypometabolic states. To better understand how organisms cope with oxygen deprivation, our lab had previously shown that when challenged with anoxia, both the nematode Caenorhabditis elegans and embryos of the zebrafish Danio rerio enter into suspended animation, where all life processes that can be observed by light microscopy reversibly halt, pending restoration of oxygen. Here, we show that both sporulating and vegetative cells of the budding yeast Saccharomyces cerevisiae also enter into a similar state of suspended animation when made anoxic on a non-fermentable carbon source. Transcriptional profiling using cDNA microarrays and follow-on quantitative real-time PCR analysis revealed a relative derepression of aerobic metabolism genes in carbon monoxide (CO)-induced anoxia, as compared to nitrogen (N2) gas-induced anoxia, consistent with the known oxygen-mimetic effects of CO. We also found that mutants deleted for components of the mitochondrial retrograde signaling pathway can tolerate prolonged exposure to CO, but not to N2. We conclude that the cellular response to anoxia is dependent on whether the anoxic gas is an oxygen-mimetic and that the mitochondrial retrograde signaling pathway is functionally important for mediating this response.