Featured Research

from universities, journals, and other organizations

Hardly any genes are activated in embryonic stem cells

Date:
April 26, 2012
Source:
Radboud University Nijmegen
Summary:
In naive embryonic stem cells not all genes are active, as previously thought. Rather these genes are “paused”, ready for action if needed.

In naive embryonic stem cells not all genes are active, as previously thought. Rather these genes are "paused," ready for action if needed. These findings were made at the Radboud University Nijmegen (the Netherlands) using modern ES cell culturing techniques.

Related Articles


The journal Cell published these results on April 27th.

Embryonic stem cells (ES cells) are special and valuable cells. ES cells are isolated from very early embryonic stages and are a model system for embryonic development. ES cells are able to divide and multiply continuously ("self-renewal") and have the capacity to specialize ("pluripotency"). They are able to differentiate into any specific cell-type of the body, including cells for organs, muscle, bone and blood. Due to these unique properties, expectations for the use of ES cells in the clinic are high, but ES cells therapies have not yet been developed to full potential.

Modern ES cell culturing techniques reveal new insights

One of the main reasons is that it is very challenging to culture these cells outside of the body (in vitro). For most organisms it's actually not (yet) possible at all to grow ES cells in vitro. For those organisms for which it is possible, the ES cells are often different from the actual cells in the body itself. This complicates research and makes the interpretation of the molecular findings in ES cells difficult. A new culturing method, developed by the ES cell expert professor Austin Smith at the Welcome Trust Stem Cell Institute in Cambridge (UK) largely solves these problems. This leads to new insights.

Using this new method, Hendrik Marks, molecular biologist at the Nijmegen Centre for Molecular Life Sciences (NCMLS) of the Radboud University Nijmegen, the Netherlands, discovered to his surprise that in naive mouse embryonic stem cells the oncogene c-myc, considered to be an essential gene for cell division and proliferation, was almost absent; there were less genes active than expected; there is hardly any inhibition on inactive genes; a lot of genes seem to be "on hold." From this state, the ES cells can efficiently specialize.

The Opposite: Genes are selectively turned on, not off

'This research gives new insights in mechanisms in ES cells to remain ES cells, but also to be able to become specialized cells. One of the dogmas in our field of research has been that it was important for ES cells to have all genes active (albeit often to a low level). ES cells would subsequently differentiate by turning genes off that are not relevant for a specific specialisation, to finally reach the correct combination of active genes for a particular specialisation', Marks explains. 'We now see the opposite: Genes are selectively turned on. However, the epigenome, the proteins present on the genome that instruct how, when and where genes should be activated, is already prepared for action. RNA Polymerase, the enzyme that transcribes the genes and thus produces the RNA, is prepared at the start of the genes. It only needs a signal to start doing its job. Moreover, the levels of the inhibiting H3K27me3 on the genes are low. That saves an additional step for the activation of the gene: the inhibiting methylgroup does not have to be removed from the histones before activation of the genes.

The research leading to these findings was supported by a large collaborative consortium ("HEROIC") supported by the European Union. This consortium, headed by prof Stunnenberg, aimed at identifying epigenetic mechanisms in mouse ES cells.


Story Source:

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


Journal Reference:

  1. Hendrik Marks, Tüzer Kalkan, Roberta Menafra, Sergey Denissov, Kenneth Jones, Helmut Hofemeister, Jennifer Nichols, Andrea Kranz, A. Francis Stewart, Austin Smith, Hendrik G. Stunnenberg. The Transcriptional and Epigenomic Foundations of Ground State Pluripotency. Cell, 2012; 149 (3): 590 DOI: 10.1016/j.cell.2012.03.026

Cite This Page:

Radboud University Nijmegen. "Hardly any genes are activated in embryonic stem cells." ScienceDaily. ScienceDaily, 26 April 2012. <www.sciencedaily.com/releases/2012/04/120426155023.htm>.
Radboud University Nijmegen. (2012, April 26). Hardly any genes are activated in embryonic stem cells. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2012/04/120426155023.htm
Radboud University Nijmegen. "Hardly any genes are activated in embryonic stem cells." ScienceDaily. www.sciencedaily.com/releases/2012/04/120426155023.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) — The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Doctor in NYC Quarantined With Ebola

Doctor in NYC Quarantined With Ebola

AP (Oct. 24, 2014) — An emergency room doctor who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus. He's quarantined in a hospital. (Oct. 24) Video provided by AP
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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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