Since the sequencing of the human genome in 2001, all our genes around 20,000 in total have been identified. But much is still unknown for instance where and when each is active. Next to each gene sits a short DNA segment, and the activity of this regulatory segment determines whether the gene will be turned on, where and how strongly. These short regulatory segments are as if not more important than the genes, themselves. Indeed, 90% of the mutations that cause disease occur in these regulatory areas. They are responsible for the proper development of tissues and organs, determining, for instance, that eye cells and only eye cells contain light receptors, while only pancreatic cells function to produce insulin. Clearly, a deeper understanding of this regulatory system its mechanisms and possibilities for malfunction may lead to advances in biomedical research, especially in developing targeted therapies for individual patients.
In spite of their importance, the "regulatory code" is not well understood. To address this problem, a research team led by Dr. Ido Amit of the Weizmann Institute Immunology Department, together with scientists from the Broad Institute in Massachusetts, including Manuel Garber, Nir Yosef and Aviv Regev, and Nir Friedman of the Hebrew University of Jerusalem, developed an advanced, automated system for mapping these sites, and then used this system to uncover important principles how these regulatory elements function. Among other things, their study, which appeared in Molecular Cell, revealed a hierarchical structure for the regulatory code. By mapping a large number of regulatory factors, the team succeeded in revealing an overall plan for gene regulation as well as the intimate details of the mechanisms involved in the immune response.
"We are seeing a race to map the regulatory code and uncover its ties to disease and human variation that is reminiscent of the race to sequence the human genome," says Amit
|Contact: Yivsam Azgad|
Weizmann Institute of Science