Growing corals in the lab reveals their complex lives
We know that human-induced environmental changes are responsible for coral bleaching, disease, and infertility. Loss of the world’s stony coral reefs – up to 30% in the next 30 years, according to some estimates – will mean loss of their services, including sequestering some 70-90 million tons of carbon each year and supporting enormous marine biodiversity. Yet despite many advances, we are still far from understanding the causes and processes contributing to the corals’ demise. Weizmann Institute researchers have developed a new experimental platform for studying coral biology at microscale resolutions, which is already providing new insights into this complex problem.
The tiny – often less than a millimeter in diameter – animals that build coral reefs create a thin layer of living tissue surrounding the calcium-based skeleton. These animals live in symbiosis with single-celled, photosynthetic algae that provide nutrients and oxygen in return for carbon dioxide and shelter. “In order to understand what happens during bleaching, when this symbiosis is broken,” says Dr. Assaf Vardi, “we need to understand what happens to these organisms at the cellular and molecular levels under various conditions.”
Vardi and his team – Orr Shapiro, Esti Kramarsky-Winter and Assaf R. Gavish of the Weizmann Institute’s Plant and Environmental Sciences Department – together with Roman Stocker of MIT (currently at ETH, Switzerland), created a system they call “coral on a chip.” For the first time, the scientists were able to examine living coral polyps in the lab, under highly controlled conditions.
This system is based on microfluidics technology, which had been developed to track cellular processes under life-like conditions. Taking a small piece of coral, Vardi and his team induced stressful conditions – in this case by increasing salt content – which caused the corals to release polyps, a process sometimes referred to as “polyp bail-out.” Settling the bailed-out polyps into prefabricated microfluidic wells, the scientists were able to observe, via continuous observation under a microscope, how miniature coral colonies called “micropropagates” grow and behave in different conditions.
Using their system, the team recorded, for the first time, the growth of individual aragonite crystals – the basic building blocks of the coral skeleton. The group was also able to directly visualize the initiation of coral disease, pointing to a little-known path of infection. Subjecting coral micropropagates to high light intensities, known to induce coral bleaching, enabled the team to follow the elimination of the symbiotic algae, one cell at a time.
Vardi’s lab group is already in the process of adapting the coral-on-a-chip system to track the nutrient and carbon cycles of reef-building corals, as well as delving further into disease and bleaching processes.
“Many corals are running out of time; it is crucial to know how our actions are affecting their survival, and how they affect ours,” he says. “Our method can help researchers investigate everything from the coral genes that affect survival, to the strategies coral use to build reefs, to their effects on the marine carbon cycle.” Indeed, as corals represent an early stage in the evolution of multicellular organisms, Vardi envisions the coral-on-a-chip platform establishing coral micropropagates as a new model system for research.
Learn more: Coral on a chip cracks coral mysteries
The Latest on: Reef-building corals
via Google News
The Latest on: Reef-building corals
- Israeli study warns of extinction danger for Red Sea coralson September 7, 2019 at 10:47 pm
The September 6 cover story of Science reports on a Tel Aviv University study warningof a phenomenon that could lead to extinction forcertain reef-building corals in the Red Sea’s Gulf of Eilat. Coral ...
- Breakdown in spawning synchrony places corals at ‘risk of extinction’on September 5, 2019 at 11:07 am
Netanyahu's ‘trust factor' with superpowers is Israel's strength ...
- Red (Sea) alert for coralon September 5, 2019 at 11:04 am
The spawning patterns of some reef-building corals in the Red Sea have completely changed over time, dramatically reducing chances of successful fertilisation, new research shows. Writing in the ...
- Breakdown in coral spawning places species at risk of extinctionon September 5, 2019 at 11:02 am
Coral reefs are among the most diverse and productive ecosystems on our planet. But due to climate change and other human stressors, reef-building corals that reproduce by means of broadcast ...
- Climate change is knocking coral mating dance out of sync, Israeli study findson September 5, 2019 at 12:47 am
Species of reef-building corals off the coast of Eilat and Aqaba may be facing extinction due to changes in the environment where they reproduce, according to two Tel Aviv University researchers.
- Friends vow to re-erect Mike's flag on Vero Beach shipwreck after Hurricane Dorianon September 4, 2019 at 4:49 pm
According to a 2018 report form Florida Department of Environmental Protection, nearly half of Florida's 45 reef-building coral species have reportedly been affected by a mysterious disease outbreak.
- USA: climate struggle is class struggleon September 3, 2019 at 2:30 am
Even a 1.5°C rise will lead to the destruction of between 70 percent and 90 percent of reef-building corals worldwide. And 2°C will mean the death of fully 99 percent of tropical reefs. As 25 percent ...
- This floating pumice rock in the Pacific could help save the Great Barrier Reefon August 26, 2019 at 9:06 pm
“It’s the right timing. So it will be able to pick up corals and other reef-building organisms, and then bring them into the Great Barrier Reef. “Each piece of pumice is a rafting vehicle. It’s a home ...
- Massive pumice 'raft' could bring marine life to help save Great Barrier Reefon August 25, 2019 at 3:41 pm
“It’s the right timing. So it will be able to pick up corals and other reef-building organisms, and then bring them into the Great Barrier Reef,” Bryan told the Guardian. “Each piece of pumice is a ...
- Hawaii braces for potential mass-coral bleaching eventon August 23, 2019 at 4:51 pm
Image courtesy of the National Oceanic and Atmospheric Administration (NOAA). Most reef building corals rely on algae, tiny dinoflagellate organisms in the genus Symbiodinium, to survive.
via Bing News