- News Home
5 December 2013 11:26 am ,
Vol. 342 ,
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
A Viral Drive to Survive
13 June 2006 (All day)
Having children can be costly, even deadly. And the larger the brood, the greater the risk. So most living things make a tradeoff, producing enough young to effectively pass on their genes without sacrificing too much of their own life span. The strategy is so universal, it even extends to nonliving entities such as viruses, according to a new study.
Viruses are the ultimate parasites. Consisting of little more than strands of DNA or RNA stuffed into a protein capsule, they are entirely dependent on their host for survival and replication. As such, the jury's still out on whether viruses are actually alive.
To see whether viruses adopt one of the near-universal signs of life--namely, the offspring tradeoff strategy--molecular biologists François Taddei and Marianne de Paepe of INSERM and the University of Paris in France watched how 16 kinds of viruses replicated in Escherichia coli bacteria. As expected, the viruses were soon replicating at a violent pace, as measured by the rate at which the bacteria burst. But when the researchers examined the offspring of this viral baby boom under an electron microscope, they noticed that many of the viruses had thin protein capsules--a sign that they themselves would probably burst before too long.
The team thinks that as viruses push to increase their numbers, the bacteria's machinery struggles to keep up and does shoddier work. "It's a case of quality versus quantity," says Taddei. These second-rate viruses are likely less able to infect bacteria, leading to less viral offspring. As a result, viruses may eventually reach a steady state in which offspring quality is not sacrificed for quantity, suggests Taddei, whose team reports its findings online today in PLoS Biology. Although not exactly analogous to the tradeoff model seen in other organisms, this is as close as viruses are likely to come, he says.
These results could have important implications for the modeling of disease virulence and transmission, says evolutionary biologist Martin Ackermann of the Swiss Federal Institute of Technology in Zurich. If other viruses behave as these do, he says, disease transmission would depend on how much a virus multiplies before the tradeoff kicks in.