Acropora digitifera genome provides new insights
In a study published this week in Nature, researchers state, "The coral genome provides a platform for understanding the molecular basis of symbiosis and responses to environmental changes." Here are some information they have discovered thus far:
- Molecular phylogenetics indicate Acropora digitifera and the sea anemone Nematostella vectensis diverged approximately 500 million years ago. The interesting aspect of this finding is that fossil records of modern corals don't date back more than 240 million years ago.
- "Despite the long evolutionary history of the endosymbiosis [between coral and zooxanthellae], no evidence was found for horizontal transfer of genes from symbiont to host."
- Acropora lacks an enzyme essential for cysteine biosynthesis, implying dependency on its symbionts for this amino acid. Acropora simply can not fully function without zooxanthellae.
- Acropora "can independently carry out de novo synthesis of mycosporine-like amino acids, which are potent ultraviolet-protective compounds." These compounds serve as life-saving protection against constant UVR exposure under the sun.
- Corals have a more complex "immunity repertoire" than those of sea anemones. This also indicates some genes play a role in symbiosis or coloniality.
- Scientists identified a number of genes with putative roles in calcification. Some of these genes are restricted to corals only. These genes could play an important role in saving corals from the effects of ocean acidification.
Earlier this year, the genome of Acropora millepora was also sequenced. Coral research is progressing nicely!