Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Retrovirus struck ancestors of chimps and gorillas millions of years ago, but not ancestral humans

01.03.2005


The ancestors of chimpanzees and gorillas were infected with a deadly retrovirus about three to four million years ago, but there is no evidence it infected ancestors of modern-day humans, according to research by genome scientists. The virus struck after humans had split off the evolutionary tree from primates, researchers said. The infection may have played a role in the evolution of such great apes as chimps and gorillas. The research appears in the April issue of the journal Public Library of Science-Biology, which is available online on March 1.



Researchers studying portions of the genome containing ’retroelements,’ also known as junk DNA, found many copies of a gene sequence in the chimp and gorilla genome that didn’t appear anywhere in the human genome. They translated that genome sequence into its corresponding protein, and discovered that it was the remnant of a retrovirus, a type of virus that copies its genetic information into the host’s genome. Evidence suggests that the ’retroelement’ originated from an external retrovirus that actively infected ape species in the past.

"The reason retroviruses are so deadly, at the genetic level, is that they have a tremendous potential to mess up a gene and interfere with its expression," explained Dr. Evan Eichler, UW associate professor of genome sciences and co-author of the study. "That can have negative effects. It’s a double-whammy: the virus infected and possibly killed off some of the population, but also caused genetic errors in survivors. Those errors would have later eliminated more of the population."


The virus had invaded the genome in the germline – in sperm or egg cells – allowing the sequence to be passed on to future generations. In those animals in which the virus was taken up next to or inside a gene – in the part of the genome that codes for the most important biological functions – the virus had an even stronger effect.

What researchers don’t understand is why the virus affected the ancestors of chimps, gorillas, and Old World monkeys, but didn’t affect the ancestors of humans or of Asian apes like orangutans and gibbons. The infections took place independently, and did not originate in a common ancestor of humans and apes. The event also took place between three and four million years ago, well after the separation of humans from apes. That split is estimated to have occurred five to seven million years ago. During that period, ancestral humans were likely to be living in the same area of Africa as great apes. African apes may have been susceptibile to the virus, or ancestral humans and Asian apes may have been resistant to it. Another possibility is that some early humans may have carried the virus, but eventually died off.

Researchers also don’t know the impact the virus had on the primate species it did affect. They found many copies of the virus in the genomes of both species, but only a tiny fraction of those copies landed in or near a gene, where it would have the greatest impact. Other studies have shown that most retroviruses typically land near or within genes. This difference may mean the animals that had the virus taken up in or near a gene didn’t survive long. Because of that natural selection, researchers believe that the virus may have had major impacts on the formation of the species we now call chimps and gorillas. The virus struck when each of the primate groups was still an incipient species with widely varying populations.

If the virus had killed off much of the population of both species, it may have created what evolutionary biologists call a population bottleneck. This much smaller group of surviving animals would then sort out most of its genetic variation in relatively fewer generations than would a larger group. This would lead to a higher probability of rare genetic variants becoming fixed in a short time. Before long, a genetically disparate population, possibly with wide variations in morphology, would have emerged, leading to today’s chimps and gorillas.

Justin Reedy | EurekAlert!
Further information:
http://www.washington.edu

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>