Scientists at MIT and Albert Einstein College of Medicine in New York have identified a new family of ocean-dwelling viruses that can’t be detected using standard lab tests. Despite their previously hidden existence, these tail-less viruses are quite common. Scientists suspect they may be abundant everywhere. “We don’t think it’s ocean-specific at all,” MIT environmental microbiologist and study leader Martin Polz told ScienceAlert. The discovery adds a key missing piece to our understanding of viral ecosystems and may lead to developments in human health, medicine, and bio-sciences.
The most common variety of viruses on Earth are double-stranded DNA (dsDNA) viruses, the most well-known of which is the Caudovirales order, also known as the “tailed” viruses. The newly discovered tail-less viruses were first identified in a new study published in the journal Nature, in which scientists incubated the viruses from seawater collected along the coast of Massachusetts and sequenced their DNA. The scientists have dubbed the tail-less viruses Autolykiviridae, in honor of Autolykos (“the wolf itself”), a character in Greek mythology known for its ability to avoid detection and capture.
Autolykiviridae viruses have shorter genomes than tailed viruses and are notably more aggressive in their predation of bacteria, playing a major consumer role in microscopic ecosystems. “They caused about 40 percent of the bacterial killing observed, despite comprising just 10 percent of the viruses that we isolated,” study co-author and microbiologist Libusha Kelly told ScienceAlert. Now that autolykiviridae have been identified, scientists have determined their presence in human digestive systems. “We’ve found related viral sequences in the [human] gut microbiome,” said Kelly, “but we don’t yet know how they influence microbial communities in the gut or how important they are for health.” While more research is necessary and forthcoming, this discovery alone is significant. “In a practical sense, it also shows how we need to alter some commonly used methods in order to capture these kinds of viruses for various studies,” Jed Fuhrman, a marine biologist at University of Southern California unaffiliated with the study, told ScienceAlert. “I’d say it is an important advance in the field.”