Featured Research

from universities, journals, and other organizations

Viral Marker Of Human Migration Suspect

Date:
October 25, 2006
Source:
Penn State
Summary:
A benign virus previously used as a marker in tracing human migration may be unreliable, according to researchers at Penn State. Results of this study also suggest that some viruses might be undergoing much higher rates of evolution than previously thought.

A benign virus previously used as a marker in tracing human migration may be unreliable, according to researchers at Penn State. Results of this study also suggest that some viruses might be undergoing much higher rates of evolution than previously thought.

"The most genetically divergent human populations are in Africa," said Laura Shackelton, a postdoctoral researcher at Penn State's Center for Infectious Disease Dynamics. "But, in the case of this virus, strains from European communities appear to be the most divergent."

The human polyomavirus, or JCV, is a small double-stranded DNA virus that is thought to be primarily transmitted from parents to their children. Infection is usually asymptomatic unless a person has a weak immune system, in which case the virus can cause neurological disease.

There are more than 14 subtypes of the virus, each primarily associated with different human populations such as African, Japanese, South Asian, and European. Population geneticists have assumed that the virus has been with humans since their emergence from Africa.

"Because of this presumed codivergence with human populations, JCV has been widely used as a genetic marker for human evolution and migration," explained Shackelton, whose findings appear this month (October) in the Journal of Virology.

The researchers note that while previous studies of genetic variation have observed some differences between the distribution of JCV and human populations, the extent of the differences in their evolutionary histories has never been fully tested.

Shackelton and her colleagues analyzed 333 genetic sequences of the virus and reconstructed their evolutionary history. They then compared this history to the reconstructed history of human populations, based on mitochondrial DNA.

"If the virus had been with humans since we were a single population, and we have almost strictly transmitted it to our children, you may expect that as populations became isolated, the virus lineages diverged as well," Shackelton noted.

However, though both sets of data indicate a period of relatively constant population size followed by a rapid increase, a closer look reveals that while human populations started to expand considerably about 50,000 years back, the viral population expanded only in the last few hundred years.

"Besides, there are several instances of one population group harboring a subtype typically associated with another group," she said. "For example one finds viruses from the Japanese and Korean subtype in the European subtype group--another incongruency."

If the virus had been strictly passed down from parent to child and had kept step with human migration, one would expect the various subtypes to group together geographically, she explains.

Shackelton added that if the co-evolution of the virus and human populations were as strict as previously thought one would not find so many differences in the family trees of the virus and humans.

Researchers also said that this study and others by the group suggest that DNA viruses may not have a slow rate of evolution as previously thought, and that the viruses like JCV might in fact be evolving twice as fast.

Other researchers of the paper include Edward C. Holmes, Penn State University; Andrew Rambaut; and Oliver G. Pybus, University of Oxford, UK. A fellowship from the Howard Hughes Medical Institute, awarded to Dr. Shackelton, supported this work. The Penn State Center for Infectious Disease Dynamics is at http://www.cidd.psu.edu/ .


Story Source:

The above story is based on materials provided by Penn State. Note: Materials may be edited for content and length.


Cite This Page:

Penn State. "Viral Marker Of Human Migration Suspect." ScienceDaily. ScienceDaily, 25 October 2006. <www.sciencedaily.com/releases/2006/10/061024214747.htm>.
Penn State. (2006, October 25). Viral Marker Of Human Migration Suspect. ScienceDaily. Retrieved July 26, 2014 from www.sciencedaily.com/releases/2006/10/061024214747.htm
Penn State. "Viral Marker Of Human Migration Suspect." ScienceDaily. www.sciencedaily.com/releases/2006/10/061024214747.htm (accessed July 26, 2014).

Share This




More Plants & Animals News

Saturday, July 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How to Make Single Serving Smoothies: Howdini Hacks

How to Make Single Serving Smoothies: Howdini Hacks

Howdini (July 24, 2014) Smoothies are a great way to get in lots of healthy ingredients, plus they taste great! Howdini has a trick for making the perfect single-size smoothie that will save you time on cleanup too! All you need is a blender and a mason jar. Video provided by Howdini
Powered by NewsLook.com
Boy Attacked by Shark in Florida

Boy Attacked by Shark in Florida

Reuters - US Online Video (July 24, 2014) An 8-year-old boy is bitten in the leg by a shark while vacationing at a Florida beach. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Newsy (July 24, 2014) A new study claims a set of prehistoric T-Rex footprints supports the theory that the giant predators hunted in packs instead of alone. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins