Regulation of apoptotic mediators reveals dynamic responses to thermal stress in the reef building coral Acropora millepora

Pernice, Mathieu, Dunn, Simon R., Miard, Thomas, Dufour, Sylvie, Dove, Sophie and Hoegh-Guldberg, Ove (2011) Regulation of apoptotic mediators reveals dynamic responses to thermal stress in the reef building coral Acropora millepora. PLoS One, 6 1: e16095.1-e16095.13. doi:10.1371/journal.pone.0016095


Author Pernice, Mathieu
Dunn, Simon R.
Miard, Thomas
Dufour, Sylvie
Dove, Sophie
Hoegh-Guldberg, Ove
Title Regulation of apoptotic mediators reveals dynamic responses to thermal stress in the reef building coral Acropora millepora
Formatted title
Regulation of apoptotic mediators reveals dynamic responses to thermal stress in the reef building coral Acropora millepora
Journal name PLoS One   Check publisher's open access policy
ISSN 1932-6203
Publication date 2011-01-24
Sub-type Article (original research)
DOI 10.1371/journal.pone.0016095
Open Access Status DOI
Volume 6
Issue 1
Start page e16095.1
End page e16095.13
Total pages 13
Place of publication San Francisco, CA, U.S.A.
Publisher Public Library of Science
Collection year 2012
Language eng
Formatted abstract
Background: Mass coral bleaching is increasing in scale and frequency across the world's coral reefs and is being driven primarily by increased levels of thermal stress arising from global warming. In order to understand the impacts of projected climate change upon corals reefs, it is important to elucidate the underlying cellular mechanisms that operate during coral bleaching and subsequent mortality. In this respect, increased apoptotic cell death activity is an important cellular process that is associated with the breakdown of the mutualistic symbiosis between the cnidarian host and their dinoflagellate symbionts.

Methodology/Principal Findings: The present study reports the impacts of different stressors (colchicine and heat stress) on three phases of apoptosis: (i) the potential initiation by differential expression of Bcl-2 members, (ii) the execution of apoptotic events by activation of caspase 3-like proteases and (iii) and finally, the cell disposal indicated by DNA fragmentation in the reef building coral Acropora millepora. In corals incubated with colchicine, an increase in caspase 3-like activity and DNA fragmentation was associated with a relative down-regulation of Bcl-2, suggesting that the initiation of apoptosis may be mediated by the suppression of an anti-apoptotic mechanism. In contrast, in the early steps of heat stress, the induction of caspase-dependent apoptosis was related to a relative up-regulation of Bcl-2 consecutively followed by a delayed decrease in apoptosis activity.

Conclusions/Significance: In the light of these results, we propose a model of heat stress in coral hosts whereby increasing temperatures engage activation of caspase 3-dependent apoptosis in cells designated for termination, but also the onset of a delayed protective response involving overexpression of Bcl-2 in surviving cells. This mitigating response to thermal stress could conceivably be an important regulatory mechanism for cell survival in corals exposed to sudden environmental changes.
Keyword Anemone aiptasia-pallida
Symbiotic sea-anemone
Great-barrier-reef
Real-time PCR
Gene-expression
Cell-death
Oxidative stress
RT-PCR
Bcl-2
Evolution
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Global Change Institute Publications
Official 2012 Collection
 
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Citation counts: TR Web of Science Citation Count  Cited 32 times in Thomson Reuters Web of Science Article | Citations
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Created: Sun, 20 Mar 2011, 00:03:02 EST