The human genome is more than 3 billion base pairs long, but not all of that information is expressed in the same way all over the body. The National Institute of Health (NIH) recently funded research to map the epigenome of various cell and tissue types. NIH’s project is known as the Roadmap Epigenomics Program. To date, researchers working for this program have mapped the genomes of over 100 different cell and tissue types. Not only does this information allow researchers to better understand which genes are activated in any given region, but it can also be used in order to develop new treatments for various diseases or defects. While the main paper was published in Nature, 20 additional papers have also been written to describe this research.

“This represents a major advance in the ongoing effort to understand how the 3 billion letters of an individual’s DNA instruction book are able to instruct vastly different molecular activities, depending on the cellular context,” said NIH Director Francis Collins in a press release. “This outpouring of data-rich publications, produced by a remarkable team of creative scientists, provides powerful momentum for the rapidly growing field of epigenomics.”

Genes are more than mere instructions that tell the body how to make proteins. They also encode a number of regulatory directives as well, including how much protein to make, when to make it, and in what cells or tissues to make it. This process is different in various regions of the body and makes up the cell or tissue’s epigenome—which the Roadmap Epigenomics Program makes a complete record of.

Image credit: John Stamatoyannopoulos and Rae Senarighi 

“Today, sequencing the human genome can be done rapidly and cheaply, but interpreting the genome remains a challenge,” co-author Bing Ren of the University of California, San Diego added. “These 111 reference epigenome maps are essentially a vocabulary book that helps us decipher each DNA segment in distinct cell and tissue types. These maps are like snapshots of the human genome in action.” 

The Roadmap makes it easier to compare epigenomic expression in different cells, which will make future research much simpler. When developing new potential therapies, it will be easier to see which genes need to be targeted in order to obtain the desired effect. The Roadmap will continue to grow as research proceeds, providing an invaluable tool to quickly and efficiently compare epigenomes in different cells.

“With this increased understanding of the full epigenome, and the datasets available to the entire scientific community, the NIH Common Fund is striving to catalyze future research, to aid the understanding of how epigenomics plays a role in human diseases, with the expectation that further studies will identify early indications of disease and targets for therapeutics,” James Anderson of the NIH concluded.