Natures Wonders- (Introduction)

by David Turell , Thursday, September 22, 2011, 22:50 (4811 days ago) @ David Turell

Back to making zombies out of insects. A virus does this to a larval form which then climbs a tree and showers other larvae with virus particles. Taken from The Scientist email I receive:-
Death-seeking caterpillar zombies -
A viral infection will drive this gypsy moth caterpillar to zombie suicide. Credit: Michael Grove
 
Like something from a horror movie, the baculovirus infects gypsy moths, turning them into automaton zombies that climb to the top of trees to die, liquefy, and rain down viral particles to infect their unsuspecting fellow caterpillars below. Healthy caterpillars, on the other hand, spend their days hiding in bark crevices and emerge only at night to feed in the safety of darkness.
 
Though pathogens controlling host behavior is not a new story, the genetic basis for these behavior changes remains a mystery. Researchers now have identified a gene, called egt, which allows the baculovirus to take the joystick and manipulate the caterpillars' climbing behavior. Researchers placed healthy and infected caterpillars into tall, sealed plastic bottles with food at the bottom. Healthy caterpillars remained below while the infected ones climbed and clung to the top of the container until they died, the researchers describe in Science. When the scientists deleted the egt gene, this behavior ceased, while reinserting the gene restored the climbing compulsion. This provides the first lead offering a genetic explanation on how some viruses are able to control their host's behavior, according to the press release.