An Ebola Surprise

Pieces of retroviruses are known littered throughout vertebrate genomes, and Anna Marie Skalka and her colleagues say that part of other viruses may also be found there. Taking an informatics-based approach, she and her colleagues compared the single-stranded RNA genomes of non-retroviruses to the genomes of 48 vertebrates, including humans and guinea pigs. As they report in PLoS Pathogens, they found that nearly half of the vertebrate genomes contained sequences from the Mononegavirales order — which includes Bornaviruses and the Filoviruses, Ebola and Marburg. The sequences date to about 40 million years ago, the researchers add. "We speculate that some of these must have provided an evolutionary advantage," Skalka tells Wired.