Navigation Links
Stem-cell research: A new genetic switching element
Date:5/22/2014

Slight modifications in their genome sequences play a crucial role in the conversion of pluripotent stem cells into various differentiated cell types. A team at Ludwig-Maximilians-Universitaet (LMU) in Munich has now identified the factor responsible for one class of modification.

Every cell contains stored hereditary information, encoded in the sequence of nucleobases that make up its DNA. However, in any given cell type, only a fraction of this information is actually used. Which genes are activated and which are turned off is in part determined by a second tier of information which is superimposed on the nucleotide sequences that provide the blueprints for protein synthesis. This so-called epigenetic level of control is based on the localized, and in principle reversible, attachment of simple chemical tags to specific nucleotides in the genome. This system plays a major role in the regulation of gene activity, and enables the selective expression of different functions in differentiated cell types.

This explains why such DNA modifications play a major role in the differentiation of stem cells. "Several unusual nucleobases have been found in the genomes of stem cells, which are produced by targeted chemical modification of the known building blocks of DNA. These 'atypical' bases are thought to be important in determining what types of differentiated cells can be derived from a given stem cell line," says Professor Thomas Carell from the Department of Chemistry at LMU. All of the unconventional bases so far discovered are derived from the same standard base cytosine. Furthermore, Carell and his team have shown in earlier work that so-called Tet enzymes are always involved in their synthesis.

Base oxidation regulates gene activity

In cooperation with colleagues at LMU, as well as researchers based in Berlin, Basel and Utrecht, Carell and his group have now shown, for the first time, that a standard base other than cytosine is also modified in embryonic stem cells of mice. Moreover, Tet is at work here too. "During the development of specialized tissues from stem cells, enzymes belonging to the Tet family also oxidize the thymidine base, as we have now shown with the aid of highly sensitive analytical methods based on mass spectrometry. The product of the reaction, hydroxymethyluracil, was previously and as it now turns out, erroneously thought to be synthesized by a different pathway," Carell explains.

The precise function of hydroxymethyluracil remains unclear. However, using an innovative method for the identification of factors capable of binding to and "reading" the chemical tags that characterize unconventional DNA bases, Carell and colleagues have shown that stem cells contain specific proteins that recognize hydroxymethyluracil, and could therefore contribute to the regulation of gene activity in these cells. "We hope that these new insights will make it possible to modulate the differentiation of stem cells causing them to generate cells of a particular type," says Carell. "It would be wonderful if we were one day able to generate whole organs starting from differentiated cells produced, on demand, by stem cell populations."


'/>"/>

Contact: Luise Dirscherl
presse@lmu.de
49-892-180-3243
Ludwig-Maximilians-Universitt Mnchen
Source:Eurekalert

Related biology news :

1. Stem-cell approach shows promise for Duchenne muscular dystrophy
2. Initial research: Mangos effects on ulcerative colitis & bone parameters in animal models
3. Research: Fructose not responsible for increase in non-alcoholic fatty liver disease
4. New research: Effects of eating half an avocado with lunch on satiety & desire to eat between meals
5. Pioneers in Alzheimers research: Research couple honored for its lifetime achievement
6. New research: Wolf Lake ancient forest is endangered ecosystem
7. DoD-funded research: Can climate change heat up conflict?
8. New Research: Modified Citrus Pectin - A Potent Anti-Cancer Therapy
9. PTSD research: Distinct gene activity patterns from childhood abuse
10. Dartmouth research: The clocks are ticking and the climate is changing
11. Influenza research: Can dynamic mapping reveal clues about seasonality?
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/12/2016)... , May 12, 2016 WearablesResearch.com ... just published the overview results from the Q1 wave ... the recent wave was consumers, receptivity to a program ... data with a health insurance company. "We ... to share," says Michael LaColla , CEO of ...
(Date:4/28/2016)... April 28, 2016 First quarter 2016:   ... 966% compared with the first quarter of 2015 The ... 589.1 M (loss: 18.8) and the operating margin was 40% (-13) ... Cash flow from operations was SEK 249.9 M (21.2) ... guidance is unchanged, SEK 7,000-8,500 M. The operating margin ...
(Date:4/15/2016)... 2016  A new partnership announced today will ... decisions in a fraction of the time it ... high-value life insurance policies to consumers without requiring ... Force Diagnostics, rapid testing (A1C, Cotinine and HIV) ... pressure, weight, pulse, BMI, and activity data) available ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... - FACIT has announced the creation of a ... Propellon Therapeutics Inc. ("Propellon" or "the Company"), to ... of first-in-class WDR5 inhibitors for the treatment of ... an exciting class of therapies, possessing the potential ... patients. Substantial advances have been achieved with the ...
(Date:6/23/2016)... June, 23, 2016  The Biodesign Challenge (BDC), a ... ways to harness living systems and biotechnology, announced its ... in New York City . ... students, showcased projects at MoMA,s Celeste Bartos Theater during ... , MoMA,s senior curator of architecture and design, and ...
(Date:6/23/2016)... June 23, 2016 Apellis Pharmaceuticals, Inc. ... clinical trials of its complement C3 inhibitor, APL-2. ... multiple ascending dose studies designed to assess the ... subcutaneous injection in healthy adult volunteers. ... as a single dose (ranging from 45 to ...
(Date:6/23/2016)... ... June 23, 2016 , ... Regulatory Compliance ... consulting, provides a free webinar on Performing Quality Investigations: Getting to ... 12pm CT at no charge. , Incomplete investigations are still a major concern ...
Breaking Biology Technology: