Ebola has been interacting with mammals for millions of years, study says
The Ebola virus has gained notoriety since the start of its outbreak early this year. Previous records say that the virus was first discovered in 1976, but latest studies date back the virus's existence as early as 20 millions years ago.
Researchers from the University of Buffalo traced the history of Filoviruses, the group of viruses where Ebola belongs, and found that it has been around Earth for more than 20 million years.
They made their discovery after studying viral fossil genes, which are bits of genetic material that animals acquire from viruses during infection. This yielded to the findings that both Ebola and the Marburg virus shared a common ancestor 16 to 23 million years ago. Both Ebola and Marburg are hemorrhagic fever viruses belonging to the Filoviridae family. This group is defined by viruses that form virions, or filamentous infectious viral particles.
The study authors found Filovirus-like genes in rodents, particularly hamsters and voles, which indicates that the Fiolovirus family dates back to these animals' ancestor. They found one fossil gene in particular, called VP35, in the same spot on the genome of four different rodent species.
Reports from Medical Daily said that "the genetic material in these fossils were more closely related to Ebola than Marburg, meaning the two lines had already begun to diverge during the Miocene Epoch, a time period that occurred five to 23 million years ago."
This debunks the previous notion that the Ebola family is around 10,000 years old.
According to Derek Taylor, lead author of the study and a professor of biological sciences at the University of Buffalo, "Filoviruses are far more ancient than previously thought. These things have been interacting with mammals for a long time, several million years."
"These rodents have billions of base pairs in their genomes, so the odds of a viral gene inserting itself at the same position in different species at different times are very small. . . .It's likely that the insertion was present in the common ancestor of these rodents," Taylor added.
The significant discovery of the Ebola's evolutionary history hopes to help researchers understand the virus more and assist them in the design and production of vaccines and treatment for the Ebola infection that has been threatening the world since it started killing thousands in West Africa.
"The more we know about the evolution of filovirus-host interactions, the more we can learn about who the players might be in the system," Taylor said.
The study was published in the journal PeerJ in September.