New type of virus found in the ocean

Typography

A type of virus that dominates water samples taken from the world’s oceans has long escaped analysis because it has characteristics that standard tests can’t detect. However, researchers at MIT and the Albert Einstein College of Medicine have now managed to isolate and study representatives of these elusive viruses, which provide a key missing link in virus evolution and play an important role in regulating bacterial populations, as a new study reports.

A type of virus that dominates water samples taken from the world’s oceans has long escaped analysis because it has characteristics that standard tests can’t detect. However, researchers at MIT and the Albert Einstein College of Medicine have now managed to isolate and study representatives of these elusive viruses, which provide a key missing link in virus evolution and play an important role in regulating bacterial populations, as a new study reports.

Viruses are the main predators of bacteria, and the findings suggest that the current view of bacterial virus diversity has a major blind spot. These conclusions have emerged through detailed analysis of marine samples led by MIT postdoc Kathryn Kauffman, professor of civil and environmental engineering Martin Polz, professor Libusha Kelly of Albert Einstein College of Medicine, and nine others. The results are being reported this week in the journal Nature.

The newly identified viruses lack the “tail” found on most catalogued and sequenced bacterial viruses, and have several other unusual properties that have led to their being missed by previous studies. To honor that fact, the researchers named this new group the Autolykiviridae— after a character from Greek mythology who was storied for being difficult to catch. And, unlike typical viruses that prey on just one or two types of bacteria, these tailless varieties can infect dozens of different types, often of different species, underscoring their ecological relevance.

Read more at Massachusetts Institute of Technology (MIT)

Image: Electron microscope images of marine bacteria infected with the non-tailed viruses studied in this research. The bacterial cell walls are seen as long double lines, and the viruses are the small round objects with dark centers.

CREDIT: Courtesy of researchers