A decade ago, scientists mapped the human genome; now, scientists have gone a step further by mapping the human epigenome. Their results were published in a group of papers in the journal Nature.
DNA only makes up a small part of our genes. The rest is made up of switches that control them, turning them on or off to express traits like height and weight, and even disease. By understanding these switches, scientists hope to learn about the origins of diseases, and develop new ways to treat or cure them.
“All our cells have a copy of the same book, but they’re reading different chapters, bookmarking different pages, and highlighting different paragraphs and words,” MIT professor of computer science Manolis Kellis, who led the effort to analyze the project data, explained in a statement. “The human epigenome is this collection of marks placed on the genome in each cell type, in the form of chemical modifications on the DNA itself, and on the packaging that holds DNA together.”
Researchers involved in the NIH Roadmap Epigenomics Consortium generated 150 billion genome sequencing reads. Kellis’s team developed an algorithm to translate the data into a map of 111 different cell types and tissues. Among their findings: DNA alterations associated with high blood pressure could be traced to switches in the heart muscle of the left ventricle. They also identified 58 specific cell changes associated with traits such as multiple sclerosis, cholesterol, and Alzheimer’s disease.
The results published by the Consortium are just the beginning. The International Human Epigenome Consortium aims to map more than 1,000 cell types, studying how they vary among individuals—an undertaking that Kellis estimates “will occupy us for at least another decade.”
View Manolis Kellis’s TED Talk: “Decoding a Genomic Revolution”
Explore the epigenome roadmap papers at Nature.