Scientists announce the completion of the Encyclopedia of DNA Elements
BY: David Adams, Science and Technology Editor
Published: Sept. 7, 2012
An international team of 440 scientists announced Sept. 5 that they had completed a roadmap to the human genome, capping the second phase of a $185 million research project nearly 10 years in the making, according to the journal Nature.
The results of the research were published in more than 20 coordinated studies in journals such as Nature and Science, among others.
"The human genome was a bit like getting 'War and Peace' in Russian," said Ewan Birney, a computational biologist at the European Bioinformatics Institute in England, in The New York Times. "It's a great book containing all of human experience, but (since) I don't know any Russian it's very hard to read."
Now scientists can use the Encyclopedia of DNA Elements, nicknamed ENCODE, as a guide to translating the complex language of DNA.
Through 1,648 experiments on 147 types of human cells, the researchers identified every biochemically-active region of DNA. This includes not only the genes, which had been mapped in the earlier Human Genome Project, but also the more than four million "switches" that control how and when genes activate within each human cell. These switches also tell cells what to become, causing some to become liver cells and others to become neurons, for example, according to the The New York Times.
These switches are found on the vast lengths of DNA between the approximately 20,000 protein-encoding regions, The Guardian reported, which accounts for "more than 98 percent of the genetic sequence" inside human cells.
Though most of this DNA was once dismissed as "junk DNA," the researchers discovered more than 80 percent of DNA is active. The Los Angeles Times said specific functions could be identified for nearly 100 percent of the DNA as research continues.
Using ENCODE, scientists now have a significant tool to determine why particular combinations of DNA variants increase vulnerability to certain diseases.
Researchers had previously found thousands of these abnormalities within DNA, but only 5 percent of them were found within genes. The rest were in the regions between genes that ENCODE has now mapped.
"Most of the changes that affect disease don't lie in the genes themselves. They lie in the switches," said Michael Snyder, a Stanford University researcher for ENCODE, in The New York Times.
A better understanding of the DNA sequence could allow scientists to create personalized medicines that would be more effective for particular people, the Los Angeles Times reported.
Treatments for diseases like multiple sclerosis, lupus, rheumatoid arthritis, Crohn's disease, celiac disease and others - which have already been linked to gene switches in the "junk" areas of DNA - would now be possible with drugs targeting those switches, The New York Times reported.
ENCODE will also help scientists understand human development before birth.
"These are the kinds of elements that make your tissues and organs grow properly, at the right time and place and containing the right kinds of cells," said Anne Ferguson, a doctorate reader at Cambridge University, in The Guardian.
Although The Guardian calls ENCODE's findings "the most significant shift in scientists' understanding of the way our DNA operates since the sequencing of the human genome in 2000," there is still a long way to go.
Birney, who led ENCODE's data analysis, estimated some mapping efforts are about 50 percent complete, according to Nature. Deeper characterization of the genome, however, may only be about 10 percent finished. That is what the next phase of ENCODE research seeks to accomplish.
"You've got to remember that these genomes make one of the most complicated things we know, ourselves," Birney said in The Guardian. "The idea that the recipe book would be easy to understand is kind of hubris. I still think we're at the start of this journey. We're still in the warm-up, the first couple of miles of this marathon."
