Viruses and bacteria from a water sample taken from the Chesapeake Bay. Photo courtesy of Dr. K. Eric Wommack, University of Delaware.

VIRUS RESEARCH: A History|SHAPES & SIZES|VIRUSES CAN HELP

University of Delaware scientist Dr. K. Eric Wommack
(seated) is leading the Extreme 2008 study of marine viruses,
with postdoctoral researchers Bekki Helton, and Shawn Polson.

In the wide, wild world of cells, the virus is the ultimate hijacker. This little protein-encapsulated bundle of genetic material, which is not even a cell, is able to take over a cell and begin making copies of itself.

While some viruses attack human cells, most viruses infect other microorganisms, namely bacteria. Better understanding the role of marine viruses and their impact on vent bacteria is a major focus of the Extreme 2008 expedition because the bacteria at the vents serve as the primary food source -- the base of the food chain -- for these oases of life in the deep sea.

K. Eric Wommack, associate professor of plant and soil sciences at the University of Delaware is leading the Extreme 2008 virus team, with co-investigators Craig Cary, professor of marine biosciences at the University of Delaware, and Shannon Williamson, director of virology at the J. Craig Venter Institute.

The scientists’ main objective is to explore the abundant, but largely unknown, viruses living within the hostile vent environment. They want to understand how viruses affect the composition and diversity of bacteria, which serve as vital links in the food chain, in addition to performing other major functions in ecosystem health.

Exploring the Viral Wilderness at the Vents

“As a group, viruses are the most abundant biological entities on Earth and contain its largest reservoir of unknown genes,” Wommack says. “We know that bacteria at the deep-sea hydrothermal vents are intimately associated with relatively abundant populations of viruses. Our goal is to explore the wilderness of viral genes existing at the vents.”

Because viruses can significantly alter the biological characteristics of their microbial hosts, in some cases changing harmless bacteria into pathogens, it is possible that viruses at the vents are intimately involved in helping microbial life cope with the challenging conditions of the deep-sea ecosystem, according to Wommack.

The viruses collected will be examined using high-throughput DNA sequencing technology and high-powered computing. Data from the research will expand efforts to describe the full extent of genetic diversity on the planet, Wommack says, likely revealing new genes and protein groups and possibly entirely new viral clades, or families of viruses.

After all, the microorganisms found at the hydrothermal vents are very different from what can be found in more accessible environments.

“We are using genetic tools to ask how different are these viruses,” Wommack says, adding, “The overwhelming answer from studies of viruses in other marine environments is that they are very different, because we have never seen anything like them.”

Virus Glossary