Mapping regulatory elements
All the tissues in the human body are made from proteins, and for every protein, there’s a stretch of DNA in the human genome that “codes” for it, or describes the sequence of amino acids that will produce it. But these coding regions constitute only about 1 percent of the genome, and scattered throughout the other 99 percent are sequences involved in regulating gene expression, or determining which coding regions will be translated into proteins. And when. In the latest issue of Nature Biotechnology, researchers at MIT and Harvard Medical School describe a new technique for systematically but efficiently searching long stretches of the genome for regulatory elements. And in their first application of the technique, they find evidence that current thinking about gene regulation is incomplete. “Conventional assays have chopped out little pieces of the genome and asked whether they’re sufficient for driving gene expression,” says David Gifford, a professor of electrical...