Featured Research

from universities, journals, and other organizations

Viral 'parasites' may play key role in maintenance of cell pluripotency

Date:
April 28, 2014
Source:
RIKEN
Summary:
"Jumping DNA" known as retrotransposons—viral elements incorporated into the human genome—may play a key role in the maintenance of pluripotency, the ability of stem cells to differentiate into many different types of body cells, new research suggests. This story is part of a fundamental rethinking taking place in genomic science.

Evolution of retrotransposon domestication in the genome: This illustration shows how long terminal repeats (LTRs), DNA sequences flanking retrotransposon segments were domesticated as regulatory sequences by mammalian genomes following a long evolutionary process.
Credit: Image courtesy of RIKEN

In a study published in Nature Genetics, scientists from the RIKEN Center for Life Science Technologies in Japan, in collaboration with the RIKEN Center for Integrative Medical Sciences, the University of Copenhagen and the Joint Genome Institute (Walnut Creek, California) have discovered that "jumping DNA" known as retrotransposons -- viral elements incorporated into the human genome -- may play a key role in the maintenance of pluripotency, the ability of stem cells to differentiate into many different types of body cells.

This story is part of a fundamental rethinking taking place in genomic science. In 2009, members of the FANTOM Consortium project reported that an important fraction of mammalian transcriptomes -- meaning the RNA transcribed from the genome -- consists of transcripts derived from retrotransposon elements, vestiges of ancient retroviruses from the same family as HIV that have in the past been considered to only parasite the genome. However, the biological function of these "jumping DNA"-associated RNA transcripts remained unknown.

In the current study on embryonic stem (ES) cells and induced pluripotent stem (iPS) cells using four high-throughput methods including cap analysis gene expression (CAGE), the researchers found that thousands of transcripts in stem cells that have not yet been annotated are transcribed from retrotransposons, presumably to elicit nuclear functions. These transcripts were found to be expressed in stem cells, but not differentiated cells. Importantly, the work showed that several of these transcripts are involved in the maintenance of pluripotency, since degrading several of them using RNA interference caused iPS cells to lose their pluripotency and differentiate.

These transcripts appear to have been recruited, surprisingly both in the human and mouse genome, where they are used to maintain the pluripotency of stem cells. Somehow, organisms including humans appear to have recruited viral elements into their genome in a way that helps to maintain the pluripotency of stem cells that allow them to regenerate. Why this is so remains a mystery for future investigation.

Although the results of the study cannot be put directly into application in regenerative medicine, knowing that retrotransposon elements are essential in the transcriptional control of iPS and ES cells is an essential clue for solving the puzzle of how to create better types of cells in future regenerative medicine studies.

"Our work has just begun to unravel the scale of unexpected functions carried out by retrotransposons and their derived transcripts in stem cell biology. We were extremely surprised to learn from our data that what was once considered genetic 'junk', namely ancient retroviruses that were thought to just parasite the genome, are in reality symbiotic elements that work closely with other genes to maintain iPS and ES cells in their undifferentiated state. This is quite different from the image given by textbooks that these genomic elements are junk," explains Dr. Piero Carninci, senior investigator of the study.


Story Source:

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


Journal Reference:

  1. Alexandre Fort, Kosuke Hashimoto, Daisuke Yamada, Md Salimullah, Chaman A Keya, Alka Saxena, Alessandro Bonetti, Irina Voineagu, Nicolas Bertin, Anton Kratz, Yukihiko Noro, Chee-Hong Wong, Michiel de Hoon, Robin Andersson, Albin Sandelin, Harukazu Suzuki, Chia-Lin Wei, Haruhiko Koseki, Yuki Hasegawa, Alistair R R Forrest, Piero Carninci. Deep transcriptome profiling of mammalian stem cells supports a regulatory role for retrotransposons in pluripotency maintenance. Nature Genetics, 2014; DOI: 10.1038/ng.2965

Cite This Page:

RIKEN. "Viral 'parasites' may play key role in maintenance of cell pluripotency." ScienceDaily. ScienceDaily, 28 April 2014. <www.sciencedaily.com/releases/2014/04/140428134010.htm>.
RIKEN. (2014, April 28). Viral 'parasites' may play key role in maintenance of cell pluripotency. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2014/04/140428134010.htm
RIKEN. "Viral 'parasites' may play key role in maintenance of cell pluripotency." ScienceDaily. www.sciencedaily.com/releases/2014/04/140428134010.htm (accessed July 25, 2014).

Share This




More Plants & Animals News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Dogs Appear To Become Jealous Of Owners' Attention

Dogs Appear To Become Jealous Of Owners' Attention

Newsy (July 23, 2014) A U.C. San Diego researcher says jealousy isn't just a human trait, and dogs aren't the best at sharing the attention of humans with other dogs. Video provided by Newsy
Powered by NewsLook.com
Professor Creates Site Revealing Where People's Cats Live

Professor Creates Site Revealing Where People's Cats Live

Newsy (July 23, 2014) ​It's called I Know Where Your Cat Lives, and you can keep hitting the "Random Cat" button to find more real cats all over the world. 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