At least, that’s what scientists thought a few days ago. Now a new study published Thursday is making researchers rethink how some viruses could infect animals.
A team at the U.S. Army Medical Research Institute of Infectious Diseases has found a mosquito virus that’s broken up into pieces. And the mosquito needs to catch several of the pieces to get an infection.
“It’s the most bizarre thing,” says Edward Holmes, a virologist at the University of Sydney, who wasn’t involved in the study. It’s like the virus is dismembered, he says.
“If you compare it to the human body, it’s like a person would have their legs, trunk and arms all in different places,” Holmes says. “Then all the pieces come together in some way to work as one single virus. I don’t think anything else in nature moves this way.”
Most viruses have simple architecture. They have a few genes — say about a half-dozen or so — that are packaged up into a little ball, 1/500th the width of a human hair.
“You can think of it like a teeny-weeny tennis ball with spikes,” Holmes says.
When the virus infects a cell, the ball latches onto the cell’s surface, opens up and pops its genes into the cell.
Poof! The cell is infected. That’s all it takes. One ball, sticking to one cell.
But that’s not the case for the Guaico Culex virus. It has five genes. And each one gets stuffed into a separate ball. Imagine five tennis balls, each with a different color: a red tennis ball, a blue one, a green one, a yellow one and an orange one.
Then to get infected with the virus, a mosquito needs to catch at least four different colored balls, researchers write in the journal Cell Host & Microbe. Otherwise the infection fails.
“The fifth …