Genome complexity: less junk (Introduction)

by David Turell , Friday, December 12, 2014, 01:07 (3635 days ago) @ David Turell

DNA folding allows DNA to create multiple functions, through 10,000 loops:-http://phys.org/news/2014-12-scientists-human-loop-ome-revealing-genetic.html-"Folding drives function,"said co-first author Miriam Huntley, a Ph.D. student in the Harvard School of Engineering and Applied Sciences working with Aiden. At the other end of these loops—far away from the genes that they regulate—lay hitherto unknown genetic switches buried deep in so-called junk DNA.-"Our maps of looping revealed thousands of hidden switches that scientists didn't know about before," said Huntley. "In the case of genes that can cause cancer or other diseases, knowing where these switches are is vital."-"The team also discovered a series of rules about how and where loops can form. "If DNA were a shoestring, you could make a loop anywhere. But within the cell, the formation of loops is highly constrained," said Rao. "The loops we see almost all span fewer than 2 million genetic letters; they rarely overlap; and they are almost always associated with a single protein, called CTCF." CTCF is known to be involved in the regulation of the 3D structure of chromatin, the building block of chromosomes.-"The most stunning discovery was about how CTCF proteins form a loop" said Dr. Eric Lander, a corresponding author on the paper. "Even when they are far apart, the CTCF elements that form a loop must be pointing at each other - forming a genomic yin and yang." Lander is director of the Broad Institute, professor of biology at MIT, and professor of systems biology at Harvard Medical School."