Viral phenomenon: Ancient microbe invaded human DNA

The invader is called bornavirus, a brain-infecting pathogen that was first identified in 1970s
Illustration of the DNA double helix. Humans carry in their genome the relics of an animal virus that infected their forerunners at least 40 million years ago, according to research published Wednesday by the British science journal Nature.

Humans carry in their genome the relics of an animal virus that infected their forerunners at least 40 million years ago, according to research published Wednesday by the British science journal Nature.

The invader is called bornavirus, a brain-infecting pathogen that was first identified in 1970s.

Scientists led by Keizo Tomonaga of Japan's Osaka University compared the DNA of a range of mammals, including humans, apes, elephants, marsupials and rodents, to look for tell-tale signatures of bornavirus code.

In the , the team found several bornavirus fragments but also in the form of two genes that may be functional, although what they do is unclear.

Until now, the only viruses known to have been handed on in vertebrates were retroviruses, which work by hijacking cellular machinery in order to reproduce.

Retroviruses are effective in infiltrating the germline -- the of , which means their sequence, or part of it, is handed on to ensuing generations.

By some estimates, retroviruses account for as much as eight percent of the human code for life.

Bornavirus has a different stealth tactic, replicating in the nucleus of infected cells.

The disease owes its name to the German town of Borna, where a regiment of cavalry horses was wiped out in 1885 by a mysterious "heated head" disease.

Later research also found the disease among sheep, llamas, ostriches, cats and cattle, although how it spreads is poorly understood.

The impact of bornavirus on the human genetic odyssey is likely to trigger fierce debate.

The big questions are whether it provided a potential cause of genetic mutation or innovation in our species, or whether it provided a source for inherited illness -- or, conversely, protection.

Bornavirus has not been clearly linked to diseases in humans, although some researchers speculate there could be a link with schizophrenia and other mental disorders.

(c) 2010 AFP

Citation: Viral phenomenon: Ancient microbe invaded human DNA (2010, January 6) retrieved 25 August 2019 from https://medicalxpress.com/news/2010-01-viral-phenomenon-ancient-microbe-invaded.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
 shares

Feedback to editors

User comments

LAG
Jan 06, 2010
Does this mean that the singularity will arrive with viral symptoms?

Jan 06, 2010
Perhaps this brain infecting virus is why we are sentient.

Jan 07, 2010
"were retroviruses, which work by hijacking cellular machinery in order to reproduce." this is not the defining characteristics of a retrovirus, but its the fact that it incorporate its dna into that of the host.

Jan 07, 2010
After 40,000,000 years they shouldn't be called bornavirus but rather bornagainvirus.

Jan 07, 2010
In fact, the defining characteristic of ALL viruses is that they hijack the cells machinery to reproduce and spread.

I suspect that since it appears 90% of the religious right has obviously been infected with the bornagainvirus, this is a source of human stupidity rather than sentience.

I guess you could call that an anti-sentient virus.

Jan 07, 2010
Viral phenomenon: Ancient microbe invaded human DNA


WHEN will this site's penchant for 'false science' end? Viruses are NOT MICROBES!!
They are merely encased strings of DNA or RNA. They have no 'goals' .. they are NOT ALIVE. They are NOT bacterial. They are mere 'packets of data' that have the ability to be released/absorbed by real life forms and by so doing, communicate information, much like an email! If i receive an email and then forward it to 1000 people, i would be functioning much like a virus-infected cell.
STOP this nonsense, PhysOrg!
Why not hire a real scientist to monitor articles here BEFORE you display them!!!

Jan 07, 2010
SF authors are already speculating that the best place to look for an Alien message would be in the introns of our DNA, since life would pass on the information generation after generation, long after a "black monolith" (as in 2001) has eroded to dust... :-)

Jan 07, 2010
Whatever we may yet discover about their common ancestry, it is sadly sloppy reporting to describe viruses as microbes...

Uh, like hair-splitting arguments over Pluto's status as is/not a 'planet', viruses and prions etc may yet find themselves re-classified as 'alive', albeit obligate parasites i.e. 'mistletoe on tree of life'...

Jan 07, 2010
Interesting that it's classified as an "animal" virus that entered the human genome 40 million years ago - and couldn't possibly be a human virus that eventually spread to animals. Good to know that we have enough 40 million year old examples of "human" DNA to prove that we evolved from such perfect stock, even though the report admits that what this virus does is unclear and how it spreds is poorly understood. It's comforting that at least 40 million years ago "humans" were not the bad guys.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more