Study helps explain how large DNA viruses undergo rapid evolution
SALT LAKE CITY – Scientists have discovered that poxviruses, which are responsible for smallpox and other diseases, can adapt to defeat different host antiviral defenses by quickly and temporarily producing multiple copies of a gene that helps the viruses to counter host immunity. This discovery provides new insight into the ability of large double-stranded DNA viruses to undergo rapid evolution despite their low mutation rates, according to a study published by University of Utah researchers in the Aug. 17, 2012, issue of Cell.
Poxviruses are a group of DNA-containing viruses that are responsible for a wide range of diseases in both humans and animals, including smallpox. Unlike smaller RNA-containing viruses, such as those that cause influenza and HIV, which are able to evade host immune responses through rapid mutation, poxviruses have larger genomes and low mutation rates and little is known about their adaptive strategies against host defenses. (click for rest of article)