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International Journal of Marine Science 2014, Vol.4, No.50, 1-22
http://ijms.biopublisher.ca
1
Research Article Open Access
The effects of temperature on gene expression in the Indo-Pacific reef-building
coral
Seriatopora hystrix
: insight from aquarium studies in Southern Taiwan
Anderson B. Mayfield
1,2
, Yi-Hsuan Chen
3
, Chang-Feng Dai
3
, Chii-Shiarng Chen
1,4,5
1 National Museum of Marine Biology and Aquarium, 2 Houwan Rd., Checheng, Pingtung 944, Taiwan, R.O.C.
2 Living Oceans Foundation, 8181 Professional Place, Suite 215, Landover, MD 20785, United States of America
3 Institute of Oceanography, National Taiwan University, 10617 No.1, Sec. 4 Roosevelt Rd., Taipei 106, Taiwan, R.O.C.
4 Graduate Institute of Marine Biotechnology, National Dong-Hwa University, 2 Houwan Rd., Checheng, Pingtung 944, Taiwan, R.O.C.
5 Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, 70 Lianhai Rd., Kaohsiung 804, Taiwan, R.O.C.
Corresponding author email
International Journal of Marine Science, 2014, Vol.4, No.50 doi: 10.5376/ijms.2014.04.0050
Received: 05 Jun., 2014
Accepted: 13 Jul., 2014
Published: 22 Aug., 2014
Copyright
©
2014 Mayfield et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Mayfield et al., 2014, The effects of temperature on gene expression in the Indo-Pacific reef-building coral
Seriatopora hystrix
: insight from aquarium studies
in Southern Taiwan, International Journal of Marine Science, Vol.4, No.50 1
-
22 (doi: 10.5376/ijms.2014.04.0050)
Abstract
Corals from upwelling reefs of Southern Taiwan have been shown to acclimate to both highly variable and abnormally
elevated temperatures. To better understand the genetic basis for Taiwanese reef coral acclimation to such temperature regimes, eight
and six genes hypothesized to be thermo-sensitive were targeted in specimens of the common stony coral
Seriatopora hystrix
and
their endosymbiotic dinoflagellate (genus
Symbiodinium
) communities, respectively, from two reefs in Southern Taiwan exposed to
two different temperature profiles. Coral specimens from Houbihu, a reef characterized by extensive, spring-tide upwelling,
displayed few provocative gene expression changes when exposed for two days to a temperature they rarely encounter
in situ
, 30
℃
.
In a second experiment, corals from Houbihu and Houwan, the latter being a reef characterized by more stable temperatures, were
exposed to either a stable (26
℃
) or a fluctuating (23-29
℃
over a 5-h period) temperature regime for seven days, and it was found
that 50% of the genes demonstrated significant changes in expression across treatments, regardless of the site of origin. This suggests
that exposure to a variable temperature for seven days may have a more dramatic effect on the sub-cellular behavior of this species
than a two-day incubation at a stable, though potentially stress-inducing, temperature.
Keywords
Acclimation; Acclimatization; Coral reef, Dinoflagellate; Endosymbiosis; Gene expression; Temperature
Background
Given the threats of global climate change (GCC)
towards scleractinian corals and the reef ecosystems
they construct, there is an urgent need to better
understand their physiological (Gates and Edmunds,
1999) and sub-cellular (van Oppen and Gates, 2006)
mechanisms of acclimatization to altered temperature
regimes (Mayfield et al., 2013a). An emerging model
for the study of GCC effects on reef corals is
Seriatopora hystrix
(Figure 1), which is amongst the
most ubiquitously distributed scleractinians in the
Indo-Pacific (Loh et al., 2001; Veron, 2000).
S. hystrix
has served as a model coral for research in diverse
locations across the Pacific Rim, such as Australia
(e.g.,
Bongaerts et al., 2011
) and Taiwan (e.g., Fan et
al., 2006; Putnam et al., 2010; Tung et al., 2006), and
is
amongst the most sensitive corals to environmental
change (Loya et al., 2001). However, in Southern
Taiwan,
S. hystrix
lives in relatively warm waters
(summer mean = ~28.5
℃
) whose temperatures can
change rapidly due not only to the tidal cycle (Meng et
al., 2008), but also to episodic upwelling (Chen et al.,
2004; Jan and Chen, 2008).
S. hystrix
is known to have limited dispersal capacity
(Ayre and Hughes, 2000), a trait that may be
associated with its ability to readily adapt to a diverse
array of environments (Nunes et al., 2009; Sanford
and Kelly, 2011). Indeed, prior work on
S. hystrix
populations from the thermally dynamic upwelling
sites mentioned above found that neither the coral
hosts nor their resident
Symbiodinium
populations
mount a gene-level molecular chaperone (heat shock
protein-70 [
hsp70
]) response when exposed to 30
℃
for 48 h (Mayfield et al., 2011; i.e., the elevated
temperature experiment [ETE]). This was hypothesized