Could plankton unlock the secrets of human biology?
Scientists use new technology to sequence the DNA of microscopic ocean creatures for the first time
By Brianna Randall
Off the west coast of Greenland, a 17-metre (56ft) aluminium sailing boat creeps through a narrow, rocky fjord in the Arctic twilight. The research team onboard, still bleary-eyed from the rough nine-day passage across the Labrador Sea, lower nets to collect plankton. This is the first time anyone has sequenced the DNA of the tiny marine creatures that live here.
Watching the nets with palpable excitement is Prof Leonid Moroz, a neuroscientist at the University of Florida’s Whitney marine lab. “This is what the world looked like when life began,” he tells his friend, Peter Molnar, the expedition leader with whom he co-founded the Ocean Genome Atlas Project (Ogap).
Moroz gestures toward Greenland’s glaciated valleys. The rapid warming here is replicating conditions from 600m years ago, when complex life forms began appearing. “We’re sailing through deep biological time right now,” he says.
Moroz and Molnar’s mission is to classify, observe, sequence and map 80% of the sea’s smallest creatures to learn more about ourselves, and the health of the planet.
Plankton and humans do not have much in common at first glance. But studying marine organisms has led to breakthrough understandings about our own brains and bodies. Observing the electrical discharges of jellyfish taught us how to restart the heart. Sea slugs showed us how memories form. Squid taught us how signals spread between different parts of the brain. Horseshoe crabs demonstrated how visual receptors work.
An unusual aspect of Moroz and Molnar’s research trips is that they are unlocking plankton’s secrets onboard sailing boats rather than engine–powered vessels – and they are not alone in this endeavour.
Every organism that lives here today is a logbook of every single adaptation that made it successful,” Moroz says. “The brain is one of the most complicated structures in the universe. Yet 70% of our knowledge about how the brain works is thanks to marine creatures. Without them, many of today’s medicines would simply not exist.
The reason he studies plankton is because their “logbook” is the longest – some single-celled marine organisms have been around for more than 3bn years. That means they have more tricks up their metaphorical sleeves than we do.
“Some groups of these marine species do not age, never develop cancers and they can fully regenerate when damaged. They are able to perform many tasks better than us,” Moroz says.