A team of Australian scientists has successfully completed an integrated genomic characterization of a reef-building coral species called Porites lutea and its microbial partners (bacteria, Archaea, algae etc.).
“Symbiotic relationships are incredibly important for thriving corals,” said lead author Dr. Steven Robbins, a researcher at the University of Queensland.
“The mostly striking example of this is coral bleaching, where corals expel their algal symbiotic partners at higher-than-normal water temperatures.”
“As algae make up the bulk of the coral’s food through photosynthesis, the coral will die if temperatures don’t cool enough to allow symbiosis to re-establish.”
“It’s possible that equally important interactions are happening between corals and their bacteria and single-cell microorganisms (Archaea), but we just don’t know.”
“To properly manage our reefs, we need to understand how these relationships work, and genomics is one of our best tools.”
“Genomics allows us to look at each organism’s entire library of genes, helping us work out how coral symbiotic relationships might support coral health.”
In the study, Dr. Robbins and his colleagues took a sample of Porites lutea from a reef near Orpheus Island, just north of Townsville, Australia.
In the lab, they separated the coral animal, its algal partner and all associated microbes, sequencing each organism’s DNA.
“Once we’ve sequenced the genomes, we use computer algorithms to look at the entire library of genes that each organism has to work with,” Dr. Robbins said.
“This allows us to answer questions like: what nutrients does the coral need, but not make itself?”
“Having high-quality genomes for a coral and its microbial partners was hugely important,” said senior author Dr. David Bourne, a researcher with the Australian Institute of Marine Science and James Cook University.
“Large advances in human medicine have been achieved in the past 20 years since the human genome was decoded. Over the next 20 years, similar knowledge of corals and how they function will emerge — this data set represents a foundation for that.”
“For the first time, we now have the genomes of a large number of the microbes that make up this coral, which is incredibly important for their survival. It’s truly ground-breaking — this is the blueprint for coral and their symbiotic communities.”
The results are published in the journal Nature Microbiology.
Steven J. Robbins et al. A genomic view of the reef-building coral Porites lutea and its microbial symbionts. Nature Microbiology, published online September 23, 2019; doi: 10.1038/s41564-019-0532-4