The gene-editing tool CRISPR-Cas9 is poised to revolutionize medicine in the coming years, and now, the platform is being put to work to boost the resiliency of corals currently in dire threat of dying off due to climate change and ocean acidification.
Biologists and geneticists at Stanford University and the University of Texas at Austin have published a report on the first use of CRISPR to modify genes in a coral species, but they excitedly proclaim that this investigation is just the beginning.
By using the bacteria-derived DNA slicer to turn off genes in the largely unexplored coral genome and then observe the outcome, researchers can gain an understanding of how the symbiotic organisms’ adaptations function on a molecular level. With this knowledge in hand, future experiments can enhance or alter genes identified to be involved with coral survival.
"I want this paper to provide an early blueprint of the types of genetic manipulations that scientists can start doing with corals," said first author Phillip Cleves in a statement. "We hope that future experiments using CRISPR-Cas9 will help us develop a better understanding of basic coral biology that we then can apply to predict – and perhaps ameliorate – what's going to happen in the future due to a changing climate."
"This is an all-hands-on-deck moment."
Because CRISPR works most efficiently when applied to an organism in the early stages of development, when there are the fewest possible cells to edit, Cleves and his colleagues traveled to the Great Barrier Reef to collect newly fertilized single-celled zygotes of the common branching coral called Acropora millepora.
They selected three target genes encoding a green fluorescent protein, a red fluorescent protein, and fibroblast growth factor 1a – a development-regulating protein thought to be involved in the establishment of new coral colonies. Results from the initial study, published in the Proceedings of the National Academy of Sciences, confirm that CRISPR can modify coral genes of which there is only one copy.
Moving forward, Cleves’ team has already started exploring genes that may help corals withstand environmental assaults. According to a recent large-scale assessment, coral bleaching events are becoming so frequent and ubiquitous that 94 percent of the world’s surveyed reefs have been severely reduced since the 1980s. As of today, an estimated 27 percent of reef ecosystems have been destroyed due to climate change and human activity.
Reef ecologist Donald Potts of UC Santa Cruz looks forward to the insights CRISPR is sure to reveal, but cautions that applying such findings toward conservation will be a complex endeavor.
He told IFLScience that the next questions we need to explore are whether genes or mutations that give tolerance to high temperatures actually exist in corals, and if so, are they in all species or only those in certain regions.
"Understanding the genetic potential of corals doesn't mean that we could – or should – attempt to modify coral genetics in the oceans, but knowledge of existing potential may well contribute to improving the design of local conservation efforts."
