Featured Research

from universities, journals, and other organizations

'Copy and paste DNA' more common than previously thought

Date:
June 28, 2010
Source:
University of Leicester
Summary:
Researchers have examined L1 (or LINE-1) retrotransposons: DNA sequences which can ‘copy and paste’ their genetic code around the genome. By breaking up genes, L1s can be responsible for some rare instances of genetic disease.

Researchers at the University of Leicester have demonstrated that movable sequences of DNA, which give rise to genetic variability and sometimes cause specific diseases, are far more common than previously thought.

In a paper published in the leading journal Cell, Dr Richard Badge and his collaborators examined L1 (or LINE-1) retrotransposons: DNA sequences which can 'copy and paste' their genetic code around the genome. By breaking up genes, L1s can be responsible for some rare instances of genetic disease.

Working in collaboration with colleagues from the Universities of Michigan and Washington and the HHMI, the researchers developed an innovative technique to find L1s, using short sequences of DNA called fosmids. These are free-floating loops of DNA, which can be easily transported into bacterial cells, and can carry pieces of human DNA.

Each fosmid can hold only a specific amount of DNA, approximately 40,000 bases. So by comparing the two ends of a piece of human DNA held in a fosmid, against their known positions in the human genome sequence*, the scientists were able to quickly and easily spot differences in size.

"We're just looking at each end of the sequence and seeing if they're the right distance apart."explains Dr Badge. "This shows us the existence of insertions (which we're interested in) and also deletions. This technology is completely unbiased -- it doesn't care what the insertion/deletion actually is, just whether it's there."

Having identified the insertions, the next step was to see if they could 'jump' in cultured human cells and how common they are -- which is where the research team found something completely unexpected.

"Previous studies suggested that lots of L1s should jump -- but don't," says Dr Badge. "But about half of the L1s we found jump really well, which was very surprising. We found about 65 elements, which had not been previously identified.

"This tells us that active human retrotransposons are much more common than we expected. Individual active L1 retrotransposons are quite rare -- but there are a lot of them."

The paper 'LINE-1 Retrotransposition Activity in Human Genomes' by Beck et al is one of three L1 studies published in the 25 June 2010 issue of Cell. A commentary in the journal describes the team's results -- 37 of the 68 elements studied being very active or 'hot' -- as "incredible."

Because of the mistaken belief in their rarity, active retrotransposons have not been as closely studied as other sources of genetic variation, but this study and the others in the journal signify a developing acceptance of their significance.

"In this field, we are constantly fighting the perception that these bits of DNA are 'junk'," observes Dr Badge. "Actually they're very active and some of them have disease relevance. They are big bits of DNA so when they jump into a gene they disrupt the gene sequence and this can cause genetic disease."

*This discovery, which was only made possible by the sequencing of the human genome, is reported in the same week that the scientific community celebrates "a decade of discovery since the Human Genome Project" and was part funded by the Wellcome Trust. Work on this project in the USA was funded by the NIH, NSF and HHMI.


Story Source:

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


Journal Reference:

  1. Christine R. Beck, Pamela Collier, Catriona Macfarlane, Maika Malig, Jeffrey M. Kidd, Evan E. Eichler, Richard M. Badge, John V. Moran. LINE-1 Retrotransposition Activity in Human Genomes. Cell, 2010; 141 (7): 1159 DOI: 10.1016/j.cell.2010.05.021

Cite This Page:

University of Leicester. "'Copy and paste DNA' more common than previously thought." ScienceDaily. ScienceDaily, 28 June 2010. <www.sciencedaily.com/releases/2010/06/100628075822.htm>.
University of Leicester. (2010, June 28). 'Copy and paste DNA' more common than previously thought. ScienceDaily. Retrieved August 2, 2014 from www.sciencedaily.com/releases/2010/06/100628075822.htm
University of Leicester. "'Copy and paste DNA' more common than previously thought." ScienceDaily. www.sciencedaily.com/releases/2010/06/100628075822.htm (accessed August 2, 2014).

Share This




More Health & Medicine News

Saturday, August 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Quintuplets Head Home

Texas Quintuplets Head Home

Reuters - US Online Video (Aug. 1, 2014) After four months in the hospital, the first quintuplets to be born at Baylor University Medical Center head home. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Ebola Patient Coming to U.S. for Treatment

Ebola Patient Coming to U.S. for Treatment

Reuters - US Online Video (Aug. 1, 2014) A U.S. aid worker infected with Ebola while working in West Africa will be treated in a high security ward at Emory University in Atlanta. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Ebola Vaccine Might Be Coming, But Where's It Been?

Ebola Vaccine Might Be Coming, But Where's It Been?

Newsy (Aug. 1, 2014) Health officials are working to fast-track a vaccine — the West-African Ebola outbreak has killed more than 700. But why didn't we already have one? Video provided by Newsy
Powered by NewsLook.com
Study Links Certain Birth Control Pills To Breast Cancer

Study Links Certain Birth Control Pills To Breast Cancer

Newsy (Aug. 1, 2014) Previous studies have made the link between birth control and breast cancer, but the latest makes the link to high-estrogen oral contraceptives. 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