Digging deep into their reproductive machinery, scientists have found startling evidence that broad classes of viruses - including those that harbor the agents that cause such diverse ailments as AIDS, the common cold and hepatitis - share functional traits that suggest they all evolved from a common ancestor.

The discovery, reported in the journal Molecular Cell, unexpectedly unites half of virology, linking large groups of viruses long thought to be functionally and evolutionarily distinct. The finding could well speed the search for vaccines and treatments for a wide range of virus-related ailments that plague both people and animals.

"Recognition of these links means that principles learned from a variety of virus systems now can be used to illuminate many others, allowing integration and generalization of knowledge across a wide range of important pathogens," says Paul Ahlquist of the Howard Hughes Medical Institute at the University of Wisconsin-Madison.

Ahlquist, the UW-Madison Kaesberg Professor of Molecular Virology and an author of the study, says the new results show that the viruses that cause ailments as distinct as the common cold, West Nile, hepatitis C, foot and mouth disease, and many others are functionally and, likely, evolutionarily related to HIV, the virus that causes AIDS.

The finding is a surprise because many of the viruses responsible for these illnesses were thought to reproduce in ways so different from one another biologically that they were long believed to be unrelated.

All viruses belong to any of six major classifications. Each class differs in important and fundamental ways, and each appears to represent major evolutionary lineages, Ahlquist says. "In each of these classes, there are important pathogens, and in each of these six classes there is lots of different biology."

Working with a much-explored model virus, Ahlquist and co-authors Michael Schwartz, Jianbo Chen, Michael Janda
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Contact: Paul Ahlquist
ahlquist@facstaff.wisc.edu
608-263-5916
University of Wisconsin-Madison
25-Mar-2002