( that the f gene stays quiet until the ...)Stolen gene allows insect virus to enter cells

that the f gene stays quiet until the third and final stage of a maggot's development, then begins to produce F proteins, which persist into adulthood. "f seems to be developmentally regulated, like a lot of Drosophila genes," says Blissard. Exactly what role the F protein plays in fruit flies remains to be answered.

At some point, perhaps after retroviruses had sprinkled host genomes with multiple copies of the f gene, a baculovirus picked it up through recombination. Unlike retroviruses, baculoviruses don't insert their genes into their hosts' genomes. They do steal genes, however, by mixing host DNA with their own. "The way they generate diversity in their genome is by recombination," Blissard says.

No matter how the original f gene moved from the fruit fly into viruses, it had to change a lot to win its current starring role in infectivity, Blissard says. He and Lung found that while viral F proteins naturally migrate to the surface of a host cell, F proteins native to the cell appear to stay on the inside. "Membrane fusion goes on all over the place inside the cell," Blissard says. "But fusion in cells is regulated by fairly large complexes of proteins. Viruses can accomplish membrane fusion with a one-protein machine." The F in fruit flies may not even be a fusion protein.

If the F protein is so important, how did baculoviruses get along without it? These viruses actually generate two types of infectious particles, Blissard explains: one type specialized to infect gut cells, and another that spreads infection in other parts of the insect. The latter type uses F to enter cells. An ancestor of today's baculoviruses "might have just existed as a diarrheal-type virus, reproducing itself at a low level in the gut, letting the host survive," Blissard hypothesizes. "Picking up the f gene may have caused a radical change in the pathology of this virus, because a virus that co-exists nicely with its host will function a lot differently than one
'"/>

Source:Cornell University News Service

Page: 1 2 3
Related biology news :

1. Researchers find how protein allows insects to detect and respond to pheromones
2. Enzyme allows B cells to resist death, leading to leukemia
3. Tiny scaffolding allows stem cells to become working fat cells
4. Looks matter to female barn swallows
5. New law for resolution allows unprecedented sharpness in fluorescence microscopy
6. Researchers identify molecular anchor that allows bacterial invasion of central nervous system
7. Algal protein in worm neurons allows remote control of behavior by light
8. Why nerve cells work faster than the theory allows
9. Parachuting allows krill to eat and run
10. Tissue engineered scaffolding allows reproduction of cartilage tissue
11. Experiments provide proof of how traveling in groups protects insects