A new roadmap to the location of DNA segments that are significant in medical, biological and evolutionary research could emerge from studies published today (Dec. 9) by scientists at Lawrence Livermore National Laboratory (LLNL) and their colleagues. The work is reported in the online version of the journal Genome Research.

Gene deserts are long stretches of DNA between genes that were once thought to have no biological function, and were dismissed as "junk DNA." As scientists probe deeper into the DNA's double helix, however, they are discovering that many of these "non-coding" segments actually play an important role in regulating gene activity.

Research last year at the U.S. Department of Energy's Joint Genome Institute (JGI) and Lawrence Berkeley National Laboratory (LBNL), for example, has shown that gene deserts contain DNA sequences that can switch genes on and off over considerable distances along the DNA molecule.

Paradoxically, the same JGI and LBNL scientists were recently able to remove giant chunks of gene desert DNA - whole chapters in the "book of life" - from laboratory mice with no apparent effect on the animals. Many of the deleted sequences are shared by mice and humans, and thus may have no function in humans as well.

In an effort to resolve the paradox and to help researchers more easily locate critical segments along the vast stretches of DNA deserts, scientists from LLNL, LBNL, and the Pennsylvania State University developed computational tools to decipher gene regulation by comparing the genomes of many different species.

When they used the tools to compare the human genome with the recently sequenced chicken genome, they discovered that gene deserts actually fall into two distinct categories: t
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Contact: Charlie Osolin
osolin1@llnl.gov
925-422-8367
DOE/Lawrence Livermore National Laboratory
8-Dec-2004