Coral Reef Info
 

Coral Reefs Articles -> Sequencing a Coral Genome

The Importance of Sequencing a Coral Species
Which Coral Species to Sequence?
A Coral ‘Laboratory Rat’
Bibliography

The National Human Genome Research Institute (NHGRI) of the National Institutes of Health (NIH) is considering a $9 million proposal to sequence a coral genome. The objective of this effort is to identify all the genes in coral DNA, determine their sequences, store information in accessible databases, and compare them with reference DNA sequences in organisms which are better studied to understand gene function. Recent advances in gene sequencing, coupled with the relatively small size of many coral genomes (1.12 x 109 bp/haploid genome) will allow this to be accomplished relatively quickly with appropriate funding. This exchange on coral genome sequencing had three general topics: (1) the importance of sequencing the genome of a reef-building coral species, (2) the specific coral species to sequence, and (3) the concept of selecting a representative species as a coral “lab rat.”
Coral Genome
DNA molecule: A (Adenine), T (Thymine), C (Cytosine), G (Guanine), S (Deoxyribose), P (Phosphate). (Credit: NHGRI)

The Importance of Sequencing the genome of a Coral Species

Pocillopora damicornis

The lace coral, Pocillopora damicornis, is an inhabitant of Indo-pacific coral reef communities. The species grow as small, bushy-shaped colonies. (Credit: Andrew Bruckner, NOAA Fisheries)


There was unanimous agreement on the importance of sequencing the genome of a reef-building coral species. Participants cited many benefits. The sequenced genome would provide a foundation for new avenues of coral scientific research and also provide a basis for technology development that could benefit coral resource management. It would yield major breakthroughs in phylogenetic systematics.

The sequenced coral genome would also be a major bonus for evolutionary genomics, since corals are representatives of the phylum Cnidaria, a sister group to all the currently sequenced metazoans. The sequenced genome would lay the foundation for all further molecular studies of coral biology. Of major interest to conservation biology would be the molecular mechanisms of stress and resistance, and also the molecular machinery of mutualism between host corals and zooxanthellae. The sequenced genome would make molecular techniques (e.g., microarrays) available to monitor the expressions of thousands of genes. For instance, genes expressed in normal versus stressed or diseased individuals could be identified, including genes that increase susceptibility or confer resistance to bleaching and disease.

Top

Which Coral Species to Sequence?


There was no consensus on the “best” species for this first genome sequencing. However, several species were repeatedly advanced throughout the exchange. The authors of the proposal had selected the lobe coral, Porites lobata, in part because of “its rising importance as a ‘laboratory rat’ in coral exotoxicology, coral cell biology,
Porites lobata

The Indo-pacific lobe coral, Porites lobata, has branches that form large lobes. The colonies may be huge, covering several meters. (Credit: Bryan Harry, National Park Service, American Samoa)

coral immunity and coral neurophysiology.” P. lobata was also chosen because of its widespread distribution in the Indian and Pacific Oceans, the Red Sea, and the Persian Gulf.

Another important advantage of Porites over others, such as the acroporids (elkhorn, staghorn and table corals) and star corals (Montastraea spp.), is that Porites lacks some of the various biochemical interfering substances that make it very difficult to apply molecular and biochemical techniques to many coral families. Finally, P. lobata and the mustard hill coral (P. asteroides) show a high degree of similarity in many of their enzymes and genes, and it should be easy to adapt technologies that would utilize the gene sequence information of P. lobata (e.g., polymerase chain reaction (PCR) gene array, enzyme-linked immunosorbent assay (ELISA), real-time PCR, and immunohistology) for further study of P. asteroides or other species of Porites.

A great star coral

The great star coral, Montastraea cavernosa, grows as a mound-shaped colony in the tropical Atlantic waters. (Credit: Andrew Bruckner, NOAA Fisheries)

In addition to Porites, species of Acropora (elkhorn corals), Montastraea (boulder star corals), and Pocillopora (lace corals) were the principal ones advanced as candidates for sequencing. Each of these species was favored for a variety of reasons, including geographic distribution, ecological and economic importance, amenability to molecular techniques, ease of laboratory rearing, growth rate, survivability, susceptibility to disease, and others. No consensus was reached about which single species or group should be sequenced first, but the participants were urged by some of their peers to lay aside their personal preferences and support the proposed project. Time was of the essence and the sequencing of the DNA of any coral would benefit all coral science and conservation management.

Top

A Coral ‘Laboratory Rat’


A great star coral

Another view of a great star coral, Montastraea cavernosa, colony. (Credit: NOAA)

There was considerable discussion exploring the concept of a coral “lab rat,” a genetically known strain that could be laboratory-reared, mass cultured, and shipped easily with a high chance of survival to any laboratory in the world. Model corals would enable rapid advances by focusing research on fundamental biological concepts broadly applicable across the taxon. Scientists could take advantage of the favorable attributes of this strain to study processes in molecular, cellular, developmental, physiological, and environmental biology. Most of the discussion on this topic focused on the specific characteristics that would be desirable in such a species. There was unanimous agreement among the participants that the coral “lab rat” concept was important and should be pursued. Model corals must be representative of coral diversity, and include Indopacific and Caribbean species, autotrophs and heterotrophs, branching, massive and plating species, and species with different algal symbionts. Because of the corals' evolutionary history, which suggests that extant corals are not a monophyletic group and different families can be both ecologically and physiologically very different, no single species would be representative of corals in general.

 

Bibliography


Bruckner, Andrew. Spring 2002. Life-Saving Products from Coral Reefs. Issues in Science and Technology Online.

The Human Genome Project, 1990-2003. 2003. Genomics and Its Impact on Science and Society: The Human Genome Project and Beyond. U.S. Department of Energy Human Genome Program.

 
Top Coral Reef News
07/19/2019
Inside the effort to map the world’s dying coral reefs from space
Off the east coast of Australia, the Great Barrier Reef stretches for 1,400 miles. It’s the largest coral reef in the world and long formed the backbone to one of the most complex and diverse natural ... more info

07/15/2019
The Current State of Coral Reefs
Coral reefs cover less than 1 percent of the Earth’s surface yet feed and shelter a significant amount of marine life, including some 4,000 species of fish. At least 500 million people rely on reefs ... more info

07/15/2019
Thirty years of unique data reveal what's really killing coral reefs
Coral reefs are considered one of the most threatened ecosystems on the planet and are dying at alarming rates around the world. Scientists attribute coral bleaching and ultimately massive coral ... more info

07/17/2019
We Finally Know Why Florida's Coral Reefs Are Dying, and It's Not Just Climate Change
A snorkeler swims among healthy Elkhorn corals off Key Largo in the Florida Keys in the early 1980s. Named for its antler-like shape for its colonies, the Elkhorn coral is one of the most important ... more info

07/20/2019
Mexico announces discovery of 5 unknown reefs in Gulf
MEXICO CITY – Researchers in Mexico say they have discovered five previously unknown coral reefs off the country’s southwestern Gulf coast. The federal Education Department says the reefs ... more info

07/15/2019
Florida's Coral Reefs Are Dying But It's Not Global Warming That Is Killing Them
Coral reefs are one of the most diverse ecosystems on Earth. But due to pollution, global warming and climate change, coral reefs are dying across the world. To find out exactly what is killing the ... more info

07/18/2019
Project aims to map coral reefs to help save them from climate change
The Allen Coral Atlas project will be like Google Street View for coral reefs, or at least that is the goal. With coral reefs in decline, the project aims to image the world’s reefs with enough detail ... more info



 
Coral Reef | Coral | Saltwater Fish | Great Barrier Reef | Reef Tanks | Glossary
Copyright © 2015 Coral Reef Info | Privacy Policy