Science & Technology

Reef-building corals and their intracellular microalgae evolve into tandem genetically

According to a new study by Pennsylvania biologists, reef-building corals such as the Elkhorn coral (Midoriishi) and the Staghorn coral (Midoriishi) and their hybrids are all depicted here, but together with the intracellular microalgae. It is evolving. Credits: Lisa Carne, Fragments of Hope Belize

The genetics of the coral-algae partnership can affect conservation.

The microalgae that inhabit the interior and nourish the host of the reef-building coral may be evolving in parallel with the inhabiting coral, so each partner is fine-tuned to meet each other’s needs. I will. A new study by biologists at Penn State University found that the genetic differences within the species of these microalga symbionts correspond to the coral species in which they live. This is a discovery that can affect the protection of these endangered species of coral.

“Midoriishi is part of a major reef-building species in the Caribbean and protects the coastlines and habitats of economically important species,” said Iliana, a professor of biology and research team leader at Penn State University. Baums says. “But these corals are endangered due to rising water temperatures, pollution, and other human changes, and their survival is partly related to the symbionts that inhabit them. Understanding the relationship between coral and its symbionts may help us improve conservation efforts. “

Reef-building corals such as Midoriishi obtain nutrients from the intracellular microalgae symbiont.The research team compared genetic differences between members of symbiotic species Symbiodinium’Fitty’ Collected from one of the Elkhorn corals (A)Cropora palmata), Closely related Staghorn coral (Acropora cervicornis), Or a hybrid that occurs when two species breed, called the fused Staghorn coral. Researchers have collected samples of symbiotic organisms from each coral species in several locations across the Caribbean Sea.Those results will be displayed online in the journal Molecular ecology..

Fish between Midoriishi and Staghorn coral

The genetic differences between the microalgae strains that inhabit reef-building corals correspond to the coral species in which they inhabit. Some of the observed differences occur in genes related to algae metabolism and physiology. This allows algae to adapt to the unique requirements imposed by each host’s microenvironment. Credits: Lisa Carne, Fragments of Hope Belize

“The genetic differences seen within the symbionts were explained primarily by the species of the host that collected them,” said a graduate student at Penn State University at the time of the study and now a postdoctoral fellow at the University of Rhode Island. One Hannah Reich said. .. “Each coral species is a unique microhabitat for the symbiont. For example, the limestone skeletons of the two coral species are different and the reflections of sunlight are different. Therefore, the symbiont maximizes the use of solar energy and In order to convert it into food, it is necessary to adapt to the conditions created by each host, after which they provide this nutrient to the hosts that depend on it for most of their nutrition. “

Researchers have found that each of the coral species S. “Fitty”. Over generations, they have formed more professional relationships. This specialization also occurred in natural coral hybrids with a relatively recent origin.

“Some of the genetic differences we have observed S.’Fitty’ The strain was contained in a gene that was predicted to have a downstream effect on the metabolism and physiology of symbiont, “said Sheila Kitchen, a postdoctoral fellow at Penn State University at the time of the study and now a postdoctoral fellow at the California Institute of Technology. Says. “These changes may allow symbiotic organisms to adapt to the unique metabolic and nutritional requirements imposed by each host’s microenvironment.”

The fidelity between the coral species and its symbiotic species is that which symbiotic strain remains intracellular when the symbiotic species is selective for the coral species that colonize and / or with a partner-selective mechanism. It remains unclear what can be enhanced if the coral host is selective. Researchers have also found that environmental factors also indirectly genetic differences between symbiont strains, for example, by affecting the symbiont before colonizing the coral, or by affecting the microenvironment within the coral host. We are noting that it may play a role in.

“Several conservation efforts are looking for ways to help corals colonize new habitats and adapt to changing environments,” Reich said. “But if the symbiont and its coral host are co-evolving and forming a preferential relationship with each other, it may not be sufficient to focus conservation activities solely on the coral host. Continued research will provide important information on how we take the best approach to conservation efforts. “

Reference: “Genome mutation of endosymbiotic dinophyceae (Symbiodinium’Fitty’) Among closely related coral hosts ”, Hannah G. Reich, Sheila A. Kitchen, Kathryn H. Stankywitz, Megan Devlin Durante, Nicole D. Fogarty, Iliana B. Baums, May 8, 2021 Molecular ecology..
DOI: 10.1111 / mec.15952

In addition to Baums, Reich, and Kitchen, the Pennsylvania State University research team includes Kathryn Stankiewicz, a graduate student in biology, and Meghann Devlin-Durante, a senior research engineer at the time of the study. The team also includes Nicole Fogarty from the University of North Carolina at Wilmington. This work was supported by the National Science Foundation.

Reef-building corals and their intracellular microalgae evolve into tandem genetically Reef-building corals and their intracellular microalgae evolve into tandem genetically

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