It’s possible that we struck lucky with this modifier, but we believe it is more likely that there are many more modifications that directly regulate our DNA.
- Magdalena Koziol
Published in the journal Nature Structural and Molecular Biology, the discovery suggests that many more DNA modifications than previously thought may exist in human, mouse and other vertebrates.
DNA is made up of four ‘bases’: molecules known as adenine, cytosine, guanine and thymine – the A, C, G and T letters. Strings of these letters form genes, which provide the code for essential proteins, and other regions of DNA, some of which can regulate these genes.
Epigenetics (epi - the Greek prefix meaning ‘on top of’) is the study of how genes are switched on or off. It is thought to be one explanation for how our environment and behaviour, such as our diet or smoking habit, can affect our DNA and how these changes may even be passed down to our children and grandchildren.
Epigenetics has so far focused mainly on studying proteins called histones that bind to DNA. Such histones can be modified, which can result in genes being switched on or off. In addition to histone modifications, genes are also known to be regulated by a form of epigenetic modification that directly affects one base of the DNA, namely the base C. More than 60 years ago, scientists discovered that C can be modified directly through a process known as methylation, whereby small molecules of carbon and hydrogen attach to this base and act like switches to turn genes on and off, or to ‘dim’ their activity. Around 75 million (one in ten) of the Cs in the human genome are methylated.
Now, researchers at the Wellcome Trust-Cancer Research UK Gurdon Institute and the Medical Research Council Cancer Unit at the University of Cambridge have identified and characterised a new form of direct modification – methylation of the base A – in several species, including frogs, mouse and humans.
Read the full story
Image: Christmas Lights
Credit: Anthony Quintano
Reproduced courtesy of the University of Cambridge
_________________________________________________