How corals adapt to day and night

Sep 12, 2008
Skeletal calice of the symbiotic coral, Stylophora pistillata. Credit: Didier Zoccola, Centre Scientifique de Monaco

Researchers have uncovered a gene in corals that responds to day/night cycles, which provides some tantalizing clues into how symbiotic corals work together with their plankton partners.

Corals are fascinating animals that form the largest biological constructions in the world, sprawling coral reefs that cover less than 0.2 % of the seafloor yet provide habitats for more than 30% of marine life. In shallow waters that don't have abundant food, corals have developed a close relationship with small photosynthetic critters called dinoflagellates.

The dinoflagellates use sunlight to produce energy for the coral, which in turn use that energy to construct mineralized skeletons for protection. The mineral production, known as coral calcification, is closely tied with the day/night cycle, though the molecular mechanism behind this synchronization is mysterious.

Aurelie Moya and colleagues have now characterized the first coral gene that responds to the light cycle; this gene, called STPCA, makes an enzyme that converts carbon dioxide to bicarbonate (baking soda) and is twice as active at night compared to daytime. The researchers found that the enzyme concentrates in the watery layer right under the calcified skeleton, which combined with studies showing that STPCA inhibitors lower calcification rates, confirms a direct role for STPCA in this process.

Moya and colleagues propose that STPCA becomes more active at night to cope with acid buildup. The calcification process requires many hydrogen atoms, which during the day can be removed by photosynthesis; at night, however, hydrogen accumulates which increases the acidity of the coral, and therefore STPCA creates extra bicarbonate as a buffer to prevent acid damage.

Citation: "Carbonic Anhydrase in the Scleractinian Coral Stylophora pistillata" by Aurélie Moya, Sylvie Tambutté, Anthony Bertucci, Eric Tambutté, Séverine Lotto, Daniela Vullo, Claudiu T. Supuran, Denis Allemand, and Didier Zoccola

Article URL: www.jbc.org/cgi/content/full/283/37/25475

Source: American Society for Biochemistry and Molecular Biology

Explore further: How do our muscles work? Scientists reveal important new insights into muscle protein

add to favorites email to friend print save as pdf

Related Stories

Senators get no clear answers on air bag safety

18 minutes ago

There were apologies and long-winded explanations, but after nearly four hours of testimony about exploding Takata air bags, senators never got a clear answer to the question most people have: whether or ...

Nicaragua: Studies say canal impact to be minimal

33 minutes ago

Officials said Thursday that studies have determined a $40 billion inter-oceanic canal across Nicaragua will have minimal impact on the environment and society, and construction is to begin next month.

Former Brown dean whose group won Nobel Prize dies

58 minutes ago

David Greer, a doctor who co-founded a group that won the 1985 Nobel Peace Prize for working to prevent nuclear war and who helped transform the medical school at Brown University, has died. He was 89.

Recommended for you

Dogs hear our words and how we say them

15 hours ago

When people hear another person talking to them, they respond not only to what is being said—those consonants and vowels strung together into words and sentences—but also to other features of that speech—the ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.