Featured Research

from universities, journals, and other organizations

Genome Mapped For Mite-borne Typhus

Date:
May 10, 2007
Source:
Uppsala University
Summary:
Scientists have mapped and analyzed the genome for mite-borne typhus. A highly unexpected finding is that bacteria, too, can have genomes with a great deal of repeated material.

Researchers at Uppsala University, in collaboration with a Korean research team, have mapped and analyzed the genome for mite-borne typhus. A highly unexpected finding, now being published in the American journal Proceedings of the National Academy of Sciences, PNAS, is that bacteria, too, can have genomes with a great deal of repeated material.

Many intracellular (living in another cell) bacteria are serious vectors of disease. These include the bacteria that cause mite-borne typhus, which accounted for more deaths among soldiers in Southeast Asia during World War II than the fighting did. Diseases that correspond to this one in the Western world are epidemic typhus and trench fever, diseases that spread via the human louse and whose genome has already been charted by the Swedish research team.

These scientists have shown that the genome of the mite-borne typhus bacterium is 200 times more repetitive than that of its close relative, the louse-borne typhus bacterium. In total, nearly 40 percent of the two million bases consist of identical gene copies of proteins that govern the interaction between the bacterium and its host cell. Today most of these copies are in the process of being erased and probably fulfill no function.

“From the point of view of evolution, these findings are astonishing. Previous studies of bacteria from aphids and body lice have presented minimalist genomes with no gene copies. The genome of the mite-borne typhus bacterium, on the other hand, has more repeated material that any other bacteria that have been mapped so far,” says Siv Andersson.

According to classical evolutionary theory, the fittest and best-adapted individual survives by beating out the weaker individuals. Studies of intracellular bacteria indicate that the process of selection can be short-circuited in small populations that go through repeated bottlenecks. This allows what would normally be rare and extreme variants to become dominant.

“The role of chance in the transmission of bacteria between mites and host animals may offer an explanation for our finding the most extreme genome in these particular bacteria. Another might be that the multiple copies for interaction with the host cell have played an important role in the evolutionary process,” says Siv Andersson.

The Swedish research team has previously shown that intracellular bacteria can develop extremely small bacterial genomes without any repeated material. Now the bacterium that causes mite-borne typhus has set a new world record in the category “the world’s most repetitive bacterial genome.”


Story Source:

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


Cite This Page:

Uppsala University. "Genome Mapped For Mite-borne Typhus." ScienceDaily. ScienceDaily, 10 May 2007. <www.sciencedaily.com/releases/2007/05/070510091729.htm>.
Uppsala University. (2007, May 10). Genome Mapped For Mite-borne Typhus. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2007/05/070510091729.htm
Uppsala University. "Genome Mapped For Mite-borne Typhus." ScienceDaily. www.sciencedaily.com/releases/2007/05/070510091729.htm (accessed April 16, 2014).

Share This



More Plants & Animals News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
Powered by NewsLook.com
In Washington, a Push to Sterilize Stray Cats

In Washington, a Push to Sterilize Stray Cats

AFP (Apr. 14, 2014) To curb the growing numbers of feral cats in the US capital, the Washington Humane Society is encouraging residents to set traps and bring the animals to a sterilization clinic, after which they are released.. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
After Attack, Officials Kill 5 Bears in Florida

After Attack, Officials Kill 5 Bears in Florida

AP (Apr. 14, 2014) Florida wildlife officials say they have killed five bears following an attack on a woman in a suburban subdivision in central Florida. Forty-five year-old Terri Frana was attacked by a large bear in her driveway Saturday. (April 14) Video provided by AP
Powered by NewsLook.com
Uruguay Opens Its First Cannabis Library

Uruguay Opens Its First Cannabis Library

AFP (Apr. 13, 2014) Uruguay opened its first Cannabis Library in Montevideo on Saturday, where people can come and read books on cannabis or take classes on how to grow the plant or even how to cook with it. Duration: 01:20 Video provided by AFP
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