Writing in the journal PLOS ONE, Japanese researchers have analysed the genetic information in a whole coral community - including the corals themselves, and the algae and micro-organisms that live on them.
Corals are made up of many hundreds of tiny little animals called polyps, which are glued together with a hard cement. Over time, this ‘skeleton’ builds up to produce the hard coral reefs you can see in the sea. Focusing on a coral called Porites australiensis, the scientists managed to assemble thousands of genetic sequences from the coral and its passengers, including an algae called Symbiodinum. They discovered that the algae was providing the coral with key amino acids - the building blocks of proteins - which it couldn’t make itself.
Coral reefs are under threat around the world as a result of human activity and climate change, so understanding more about their genetics - and the genes in the organisms that live on them - is a crucial piece of efforts to preserve these incredible habitats.