Biologists are working with engineers to develop new tools to accelerate the development of medicines derived from marine animals, focusing on ocean-going robots with onboard DNA-sequencing gear. They foresee fleets of autonomous submersible robots trolling the ocean like electronic bloodhounds to sniff out snippets of the animals’ DNA in seawater—and then gathering and analyzing this so-called environmental DNA, or eDNA.

“The ultimate goal is an underwater vehicle that collects environmental DNA samples, sequences them and then sends the data back to the lab,” says Kobun Truelove, senior research technician at the Monterey Bay Aquarium Research Institute in California. “We would like to set up a network where you would have these autonomous vehicles out there sampling and then basically be getting the data back in real time.”

More than 1,000 marine-organism-derived compounds have shown anticancer, antiviral, antifungal or anti-inflammatory activity in medical assays, according to a database compiled by the Midwestern University Department of Marine Pharmacology. The U.S. Food and Drug Administration has approved 15 drugs derived from marine organisms, including ones for chronic pain and high cholesterol. Another 29 marine animal-derived compounds are now in clinical trials, according to the database.

Marine invertebrates are a key target of biomedical research because the animals—mostly attached to the seabed and unable to move—have evolved sophisticated chemical defenses to fend off fish, turtles and other predators in their environment. Research has shown that the natural toxins that comprise these defenses can be toxic to cancer cells and human pathogens. These sea creatures “make a broad range of different chemistries, things that synthetic chemists never thought of making,” says Barry O’Keefe, who have also identified compounds produced by bacteria living symbiotically with marine invertebrates. Once scientists have a suitable sample of eDNA and it’s been sequenced, they say, they can identify compounds the organisms are capable of producing. Then researchers can synthesize the compounds and test them to see if they have medicinal properties…

Collection of eDNA promises to be faster and less costly than the complex method commonly used   collect marine specimens—one that Amy Wright, director of the natural products group at Florida Atlantic University’s Harbor Branch Oceanographic Institution, likens to a treasure hunt. Currently, research vessels on weekslong expeditions launch submersible vehicles equipped with clawlike grabbers and suction tubes for gathering specimens. Once the vehicles and their payload are back on the ships, researchers preserve them and deliver them to labs, where their genomes are sequenced. The entire process can take weeks and is expensive. Just paying the crew to operate a research vessel for a single day can cost $35,000, according to the National Science Foundation.

Excerpts from  Eric Niile, Finding New Drugs From the Deep Sea via ‘eDNA’, WSJ, Sept. 3, 2022