Genetic Light Switches

Scientists are one step closer to making sense of the human genome. They have located and sequenced over 10,000 DNA regions that turn genes on and off like a light switch.

These regions, called "promoters", were discovered in fibroblasts - human cells that form connective tissues throughout the body. By knowing more about DNA-controlling promoters, scientists learn how the nearly 8,000 active genes in our body work.

Understanding genetic light switches will help scientists determine how cells are programmed to perform specialized functions. Nearly all the cells in the human body have the same genetic content, but cells in your stomach express very different information than cells in your brain. With this new information, scientists are a step closer to identifying the genetic cues that make that possible.

To make this discovery possible, researchers at University of California, Los Angeles used cutting edge laboratory techniques and specially designed computer programs.

This "promoter map," which is published in the June 29 electronic edition of Nature, will serve as a future framework for genetic analysis in human tissues other than fibroblasts.