Epigenetics is a branch of genetics that studies modifications to the DNA which affect gene activity.
All the cells in the body have the same DNA sequence (genome), but it is how this DNA sequence is interpreted that results in the formation of different cell types. Epigenetic changes control how a DNA sequence is interpreted, specifically how different genes are switched on and off in different cell types, tissues and organs.
One of the most studied epigenetic marks is the addition of a very small chemical modification called a methyl group to DNA, which turns associated genes off. Methyl groups are always added to the DNA base cytosine and so this chemical modification is called 5-methylcytosine (5mC). Babraham Institute scientists are involved in researching the role of another DNA chemical modification in mammals called 5-hydroxymethyl-cytosine (5hmC), which is believed to be important for stem cell function, helping to define how the body develops. 5hmC may be a separate epigenetic mark or possibly be part of the process which removes methyl groups from DNA, allowing genes to be switched on again. Decoding the ‘epigenome’ will provide greater understanding of how cells are regulated and has major implications for regenerative medicine and how cells such as stem cells can be controlled.
Professor Shankar Balasubramanian FRS, of the University of Cambridge Chemistry Department and Cancer Research UK Cambridge Research Institute, and his PhD student Michael Booth invented new chemistry to allow the recently discovered base 5hmC to be sequenced in DNA at single base resolution. This was not possible using existing methods. In a fruitful collaboration between the Cambridge group (led by Balasubramanian) and the Babraham Institute (led by Professor Wolf Reik FRS), this method was applied to sequence 5hmC and 5mC in embryonic stem cell genomic DNA.
Balasubramanian, whose group previously co-invented Solexa sequencing, explained, “Sequencing DNA is becoming an increasingly important part of science and medicine and we are pleased to have met the challenge of finding a way to sequence this important new base modification.”
Michael Booth, co-inventor of the technique, said, “We developed a chemistry that was specific for this new modified DNA base, 5hmC. This allowed us to accurately distinguish between 5mC and 5hmC at single base resolution in the genome.”
Dr Miguel Branco from the Babraham Institute who is joint lead author commented, “There was a real need in the field for a technique that would map both 5hmC and 5mC in the genome quantitatively and at high resolution. We applied this new technology to embryonic stem cells and immediately recognised its power in furthering our understanding of the biological functions of these DNA modifications.”
Professor Wolf Reik who led the study at the Babraham Institute, which receives strategic funding from the Biological Sciences Research Council (BBSRC) said, “It has recently become apparent that in addition to DNA methylation, there are other modifications of DNA, such as for example hydroxymethylation. This suggests that DNA modifications are more dynamic than we previously thought. With the new method we are now in a position to map these modifications at great precision, and to relate them to stem cell function, ageing, and perhaps more generally to how the environment interacts with the genome.”
The Babraham Institute undertakes world-leading life sciences research to generate new knowledge of biological mechanisms underpinning ageing, development and the maintenance of health. Professor Michael Wakelam, Director of the Babraham Institute, said, “This is an excellent example of collaboration between research institute and University research scientists. The work will improve our knowledge of how cells develop, with potential long-term benefits to society.” In addition to the BBSRC, this research was supported by the MRC, the Wellcome Trust and the EU.
Professor Daan Frenkel ForMemRS, Head of the Department of Chemistry at the University of Cambridge, commented, “This new technique, which reflects the continued innovative work of Professor Balasubramanian and his team, will dramatically change how epigenetic research is conducted. By collaborating with experts at Babraham, they have also demonstrated how the technique will have significant implications for regenerative medicine.”
Publication details:
Quantitative sequencing of 5-methylcytosine and 5-hydroxymethylcytosine at single base resolution
Michael J. Booth, Miguel R. Branco, Gabriella Ficz, David Oxley, Felix Krueger, Wolf Reik & Shankar Balasubramanian
Notes
Professor Wolf Reik is a Group Leader at the Babraham Institute, an associate faculty member at the Wellcome Trust Sanger Institute and is affiliated with the Centre of Trophoblast Research and the University of Cambridge.
Dr Miguel Branco is now a Next Generation Fellow from the Centre for Trophoblast Research
The Babraham Institute
The Babraham Institute, which receives strategic funding from the Biotechnology and Biological Sciences Research Council (BBSRC), undertakes international quality life sciences research to generate new knowledge of biological mechanisms underpinning ageing, development and the maintenance of health. The institute received £22.4M investment from BBSRC in 2010-11. The Institute’s research provides greater understanding of the biological events that underlie the normal functions of cells and the implication of failure or abnormalities in these processes. Research focuses on signalling and genome regulation, particularly the interplay between the two and how epigenetic signals can influence important physiological adaptations during the lifespan of an organism. By determining how the body reacts to dietary and environmental stimuli and manages microbial and viral interactions, we aim to improve wellbeing and healthier ageing. (www.babraham.ac.uk)
University of Cambridge
The University of Cambridge’s mission is to contribute to society through the pursuit of education, learning and research at the highest international levels of excellence.
Cambridge’s reputation for excellence is known internationally and reflects the scholastic achievements of its academics and students, as well as the world-class original research carried out by its staff. Some of the most significant scientific breakthroughs occurred at the University, including the splitting of the atom, invention of the jet engine and the discoveries of stem cells, plate tectonics, pulsars and the structure of DNA. From Isaac Newton to Stephen Hawking, the University has nurtured some of history’s greatest minds and has produced more Nobel Prize winners than any other UK institution with over 80 laureates.
About BBSRC
The Biotechnology and Biological Sciences Research Council (BBSRC) invests in world-class bioscience research and training on behalf of the UK public. Our aim is to further scientific knowledge, to promote economic growth, wealth and job creation and to improve quality of life in the UK and beyond.
Funded by Government, and with an annual budget of around £445M, we support research and training in universities and strategically funded institutes. BBSRC research and the people we fund are helping society to meet major challenges, including food security, green energy and healthier, longer lives. Our investments underpin important UK economic sectors, such as farming, food, industrial biotechnology and pharmaceuticals.
For more information about BBSRC, our science and our impact see: www.bbsrc.ac.uk
For more information about BBSRC strategically funded institutes see: www.bbsrc.ac.uk/institutes
About the Wellcome Trust
The Wellcome Trust is a global charitable foundation dedicated to achieving extraordinary improvements in human and animal health. It supports the brightest minds in biomedical research and the medical humanities. The Trust's breadth of support includes public engagement, education and the application of research to improve health. It is independent of both political and commercial interests. www.wellcome.ac.uk
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Contact details:
Professor Shankar Balasubramanian, University of Cambridge
Email: sb10031@cam.ac.uk
Professor Wolf Reik
Email: wolf.reik@babraham.ac.uk
Dr Anja Drozd
External Relations Officer, The Babraham Institute
Email: anja.drozd@babraham.ac.uk
Tel: +44 (0)1223 496206
The Babraham Institute
Babraham Research Campus
Cambridge CB22 3AT
United Kingdom
Genevieve Maul,
Office of Communications, University of Cambridge
Email: Genevieve.maul@admin.cam.ac.uk
Tel: direct, +44 (0) 1223 765542, +44 (0) 1223 332300
Mob: +44 (0) 7774 017464
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