Rescuing Reefs from the Inside Out

Cleves already has developed agreements with other researchers from UC campuses to use his systems. The lifelong oceans aficionado is clearly thrilled by the scientific possibilities. 

“When I was a kid, I was enamored by the oceans, even though they are far away from Arkansas,” said Cleves. “They are one of the last frontiers on Earth. They’re unexplored, and there's so much biodiversity down there.”
 
Coral reefs highlight that biodiversity. These hotspots — the “rainforests of the sea” — are thought to support up to 25% of all known marine life. Cleves was fascinated by how these oases of life could exist in nutrient-poor waters. 
 
In an undergraduate biology class, he learned how corals formed a symbiotic relationship with algae growing inside their cells. Despite their resemblance to plants or rocks, corals are actually animals. Algae provides its coral host with its color and 90% of its energy needs. Cleves wondered how one organism could live inside another and has been trying to answer that question ever since.

Coral reefs are collapsing due to rapidly warming oceans. When water temperatures spike, corals release their algae, which causes them to become bleached in appearance and starve to death. The world has lost around 40% of its corals in the past 40 years.
 
Cleves spent the past 10 years developing CRISPR-based systems that allow researchers to genetically modify and test gene function in corals. His lab discovered genes that control heat tolerance and those that help build reefs’ calcium carbonate skeletons. By understanding how algae symbiosis breaks down during coral bleaching, Cleves hopes to predict which corals have the strongest ability to survive climate change, which can then guide conservation efforts. For instance, scientists could proactively establish more resilient corals in cooler waters.

“With these new genetic tools, we have the ability to understand how organisms will adapt, how ecosystems will be structured, and what we can do to save important ecological functions that support our lives,” said Cleves. “That feeds back into biomedicine. By discovering how weird organisms like corals work at the genetic level, we can discover new molecules that can revolutionize biomedicine. It really is a brave new world.”

Cleves referred to CRISPR, which was first identified in a salt marsh's microorganism’s repeating DNA sequences, and paclitaxel, a chemotherapy drug derived from Pacific yew bark that blocks cells from dividing. He suspects his research into microbial control of animal cells could similarly lead to new therapeutics.

“There are molecular machines out there that could solve diseases and the climate crisis,” said Cleves. “We just need to go out and find them.”