A New Epigenetic Modification Has Been Revealed that Could Open Up the Field of Epigenetics, Says Research Team from the University of Cambridge
Epigenetic modification research keeps gaining momentum as the revolutionary science is quickly becoming one of the most important fields of research to describe our genetic expressions. But, before we discuss the most recent breakthrough in epigenetic research, we must first set the table for you. So, hang in there and I promise you, it will be well worth it.
DNA Methylation and Histone Modification
The studying of histones that bind to DNA has the primary focus of epigenetic modification research. These histones can be modified, which can result in genes being read or not. There are basically 5 different types of Histone proteins called H2A,H2B, H3 and H4 which form a bead on which the DNA is wrapped (with two molecules each, so a total 8 protein molecules in the bead and one called H1 between two beads). Within the histones, it is actually the amino acids that are modified.
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. This process is referred to as DNA Methylation.
The four bases are namely Adenine, Thymine, Guanine ad Cytosine. It has already been more than 60 years now, since scientists discovered that C can be modified directly. This process is executed as small molecules of carbon and hydrogen bind to this base and allow certain genes to be turned on and off, or to ‘dim’ their activity. It is estimated that roughly 75 million, or one in ten, of the Cs in the human genome are methylated. 
However, published on December 21st, 2015 in the journal Nature Structural and Molecular Biology, a major new discovery suggests there exists many more DNA modifications that we did not know about.
Epigenetic Modification – Direct Methylation of the Base A
Discovered by Magdalena J Koziol, Charles R Bradshaw, George E Allen, Ana S H Costa, Christian Frezza, & John B Gurdon at the Wellcome Trust-Cancer Research UK Gurdon Institute and the Medical Research Council Cancer Unit at the University of Cambridge have identified and characterized a new form of direct modification – methylation of the base A – in several species, including frogs, mouse and humans.  
Although, methylation of A appears to be far less common that C methylation, occurring on around 1,700, the research team urges that they are very important and spread across the entire genome. Although, it does not seem to occur on sections of our genes known as exons, which provide the code for proteins.
Opening Up the Field of Epigenetics
“These newly-discovered modifiers only seem to appear in low abundance across the genome, but that does not necessarily mean they are unimportant,” says Dr Magdalena Koziol from the Gurdon Institute. “At the moment, we don’t know exactly what they actually do, but it could be that even in small numbers they have a big impact on our DNA, gene regulation and ultimately human health.”
“It’s possible that we struck lucky with this modifier,” says Dr Koziol, “but we believe it is more likely that there are many more modifications that directly regulate our DNA. This could open up the field of epigenetics.”
The field of epigenetic is growing rapidly and has the potential to redefine our interactions with nature and each other. Stay tuned for follow up articles that will explore these findings in greater depth.
 DNA methylation patterns and epigenetic memory Adrian Bird published in Genes & Dev. 2002. 16: 6-21
 http://www.nature.com /nsmb /journal/ vaop/ ncurrent /full /nsmb .3145.html#contrib-auth