Startling links

broad classes of viruses, including those that harbour agents of ailments like aids and the common cold, share functional traits, discovered scientists from the University of Wisconsin (uw)-Madison, usa. The discovery 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 (www.sciencedaily.com , March 26, 2002).

Working with a much-explored model virus, the scientists showed that the key features of replication run parallel in three of the six broad classes of viruses. It turns out that while the viruses in these three groups build different structures to move between host cells, basic mechanisms in their replication is the same. The basic goal of all the viruses is to reproduce and pass along their genes using the reproductive machinery of the cells they invade to make virions -- infectious particles that act like seeds to infect other cells.

The parallel features discovered involve the mechanisms by which viruses replicate their genetic information after they commandeer the cells of the hosts they infect. Some viruses related by the discovery replicate by switching their genes between rna and dna, while others store and replicate their genes only as rnas.

On the basis of such findings the researchers concluded that viruses which cause ailments as distinct as common cold, West Nile, hepatitis c and many others, are functionally same and are most probably related to hiv in evolutionary terms.

"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 generalisation of knowledge across a wide range of important pathogens," says Paul Ahlquist of the Howard Hughes Medical Institute at the uw-Madison University.