Featured Research

from universities, journals, and other organizations

Enzyme Necessary For DNA Synthesis Can Also Erase DNA

Date:
June 9, 2009
Source:
Uppsala University
Summary:
Scientists have discovered a new mechanism behind an important process that causes a rapid reduction of DNA in the chromosomes of bacteria. The findings advance our knowledge of how DNA content has been reduced, which is something that has occurred in bacteria that live as parasites inside the cells of other organisms.

In this week's edition of Proceedings of the National Academy of Sciences, PNAS, Uppsala University scientists describe a new mechanism behind an important process that causes a rapid reduction of DNA in the chromosomes of bacteria. The findings advance our knowledge of how DNA content has been reduced, which is something that has occurred in bacteria that live as parasites inside the cells of other organisms.

The amount of DNA in the chromosomes of bacteria can change rapidly, either by increasing, so-called gene amplification, or by decreasing, so-called gene deletion. These processes are evolutionarily very important, and the discovery of a new mechanism that is involved when DNA disappears is of fundamental importance to our understanding what influences the stability of chromosomes and why the amount of DNA can decrease in certain types of bacteria. "How rapidly and by what mechanisms DNA can disappear from the chromosome is a central genetic and evolutionary question," says Professor Dan I Andersson, the lead author of the study.

Previously these types of large gene deletions, have mostly been studied in artificial model systems with two long identical and neighboring DNA sequences. Normal spontaneous deletions, on the other hand, are often remote from each other and lack sequence identity.

In the current study, the PhD student Sanna Koskiniemi has carried out comprehensive genetic analyses of Salmonella mutants and her results show that a special type of DNA-synthesizing enzymes are necessary if spontaneous deletions are to be formed in the bacteria. This new function has never before been described in these enzymes. By genetically inactivating or overproducing these enzymes, the researchers were able to show that the deletion rates decreased or increased by up to 30 times.

These findings can explain how and why the DNA content of different organisms varies and what genetic mechanisms govern this, says Professor Dan Andersson, who suggests that bacteria that live either as parasites inside cells or in symbiosis with other organisms are of special interest with regard to this new mechanism.

These bacteria often have small chromosomes because DNA has disappeared during evolution. With these new findings we can better understand and predict how DNA is eliminated from chromosomes.


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. "Enzyme Necessary For DNA Synthesis Can Also Erase DNA." ScienceDaily. ScienceDaily, 9 June 2009. <www.sciencedaily.com/releases/2009/06/090608182541.htm>.
Uppsala University. (2009, June 9). Enzyme Necessary For DNA Synthesis Can Also Erase DNA. ScienceDaily. Retrieved August 30, 2014 from www.sciencedaily.com/releases/2009/06/090608182541.htm
Uppsala University. "Enzyme Necessary For DNA Synthesis Can Also Erase DNA." ScienceDaily. www.sciencedaily.com/releases/2009/06/090608182541.htm (accessed August 30, 2014).

Share This




More Health & Medicine News

Saturday, August 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

Reuters - US Online Video (Aug. 30, 2014) California lawmakers pass a bill requiring universities to adopt "affirmative consent" language in their definitions of consensual sex, part of a nationwide drive to curb sexual assault on campuses. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
3 Things To Know About The Ebola Outbreak's Progression

3 Things To Know About The Ebola Outbreak's Progression

Newsy (Aug. 29, 2014) Here are three things you need to know about the deadly Ebola outbreak's progression this week. 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