Navigation Links
Corals can sense what's coming
Date:11/18/2011

Australian scientists have thrown new light on the mechanism behind the mass death of corals worldwide as the Earth's climate warms.

Coral bleaching, one of the most devastating events affecting coral reefs around the planet, is triggered by rising water temperatures. It occurs when the corals and their symbiotic algae become heat-stressed, and the algae which feed the corals either die or are expelled by the coral.

There have been seven major bleaching events globally in the past 30 years, the most recent being in 2010 across the Indian Ocean and Coral Triangle. Australia's Great Barrier Reef has suffered eight events since 1980, the worst being in 2002 when 55% of the total reef area was affected. The frequency of these events appears to be increasing.

Now a team of scientists from the ARC Centre of Excellence for Coral Reef Studies and James Cook University has shown that a complex cascade of molecular signals leading up to the self-inflicted death of corals and their symbiotic algae is triggered as sea water begins to warm.

Working with Acropora corals from the reef at Heron Island, the researchers found the cascade begins at ocean temperatures as much as 3 degrees lower than those normally associated with coral bleaching.

And the process culminates in 'apoptosis' or programmed cell-death a situation in which living organisms (including corals and humans) deliberately destroy their weakened or infected body cells, effectively a form of 'cell suicide' or amputation designed to protect the organism as a whole.

"Our results suggest that the control of apoptosis is highly complex in the coral-algae symbiosis and that apoptotic cell death cascades potentially play key roles in tipping the cellular life or death balance during environmental stress prior to the onset of coral bleaching," explains lead author Dr Tracy Ainsworth.

"It is also clear that this chain reaction responds significantly to subtle, daily changes in the environment and to sea temperatures which were generally thought till now to have little impact on the function of coral and its symbiotic algae."

Paradoxically, the team's research identified molecular signals both promoting and discouraging programmed cell-death in the corals.

This has led them to a theory that corals respond to the stresses caused by warming sea water by killing off some of the cells, while strengthening others in order to stage a possible recovery after the hot water has moved off the reef and conditions have returned to normal.

"This would explain why some corals are able to recover quite quickly from a bleaching event, if it has not gone too far.

"It is far too early to speculate, but understanding the recovery process for any living organism is always a big help, as human medicine has constantly demonstrated, Dr Ainsworth says.

"The next step in our research will be to see how we can use this new insight into the processes of coral bleaching to understand their recovery mechanisms. We also need to know more about how this process works at lower temperatures, or under varying temperatures.

"That in turn will lead us to explore ways that coral reef managers and users can perhaps minimise other stresses on the reef in order to give it the best possible chance of recovery from bleaching."

However the team cautions that "further study of the tissue function and cellular differentiation and recovery processes in coral is needed before this complicated cell death system can be fully understood".


'/>"/>
Contact: Tracy Ainsworth
tracy.ainsworth@jcu.edu.au
61-747-814-442
ARC Centre of Excellence in Coral Reef Studies
Source:Eurekalert

Related biology news :

1. Fishy lawnmowers help save Pacific corals
2. Study identifies molecules used by certain species of seaweed to harm corals
3. New study of Glovers Reef challenges whether corals will benefit from Marine Reserves protection
4. New study of Glovers Reef challenges whether corals will benefit from Marine Reserves protection
5. Human pathogen killing corals in the Florida Keys
6. How soft corals defy their environment
7. Coral algae (symbiodinium) discovered in black corals at never seen before depths
8. NOAA webcasts corals research to nations classrooms live from undersea lab
9. How corals fight back
10. Baby corals dance their way home
11. Not a fish story: Protected corals increase fishing profits
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/28/2016)... BANGALORE, India , April 28, 2016 ... subsidiary of Infosys (NYSE: INFY ), and Samsung ... global partnership that will provide end customers with a ... and payment services.      (Logo: http://photos.prnewswire.com/prnh/20130122/589162 ... for financial services, but it also plays a fundamental part ...
(Date:4/28/2016)... First quarter 2016:   , Revenues amounted to ... of 2015 The gross margin was 49% (27) ... operating margin was 40% (-13) Earnings per share rose ... was SEK 249.9 M (21.2) , Outlook   ... The operating margin for 2016 is estimated to exceed ...
(Date:4/26/2016)... and LONDON , April ... part of EdgeVerve Systems, a product subsidiary of ... today announced a partnership to integrate the Onegini ...      (Logo: http://photos.prnewswire.com/prnh/20151104/283829LOGO ) ... their customers enhanced security to access and transact ...
Breaking Biology News(10 mins):
(Date:4/27/2016)... RESEARCH TRIANGLE PARK, N.C. , April 27, ... ) announced today that Martine Rothblatt , Ph.D., ... provide an overview and update on the company,s business ... Care Conference. The presentation will take place ... Time, and can be accessed via a live webcast ...
(Date:4/27/2016)... ... ... Global Stem Cells Group CEO Benito Novas announced that Duncan Ross, Ph.D. ... Labs in Miami. , In 2004, Ross received his Ph.D. in Immunology from the ... the suppression of graft vs. host disease (GVHD) under UM Professor Robert Levy Ph.D. ...
(Date:4/26/2016)... ... April 26, 2016 , ... BaseHealth , the ... the company as Chief Business Officer. Arianpour, a genomics pioneer and visionary commercial ... was most recently Chief Commercial Officer of Pathway Genomics. He has held senior ...
(Date:4/26/2016)... ... ... BioFactura, Inc ., a biopharmaceutical research and manufacturing company, announced today the ... significant oversubscription of the original $1.5M target. The funds will be used to ... , Chief Executive Officer and President, Darryl Sampey founded BioFactura in 2004 ...
Breaking Biology Technology: