Ancient viruses helped speedy nerves evolve
Ancient viruses have really gotten on our nerves, but in the best of ways.
One particular retrovirus — embedded in the DNA of jawed vertebrates — helps turn on production of a protein needed to insulate nerve fibers, researchers report February 15 in Cell. Such insulation, called myelin, may have helped make speedy thoughts and complex brains possible.
The retrovirus trick was so handy, in fact, that it showed up many times in the evolution of vertebrates with jaws, the team found.
Retroviruses are RNA viruses that make DNA copies of themselves to embed in a host’s DNA. Rarely, these insertions can become a permanent part of who we are, being passed down from parent to offspring. Scientists once thought remnants of of these ancient viruses — known as jumping genes or retrotransposons — as genetic garbage, but that impression is changing, says neuroscientist Jason Shepherd, who was not involved in the study.
“We’re finding more and more that these retrotransposons and retroviruses have influenced the evolution of life on the planet,” says Shepherd, of the University of Utah Spencer Fox Eccles School of Medicine in Salt Lake City. [Continue reading…]