Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Access to DNA secrets yields better understanding of genes, possible tool for disease diagnosis

08.07.2004


A new technique for examining DNA is giving scientists a more detailed picture of which genes have the propensity for activation, offering a new tool for understanding how genes function and possibly for diagnosing disease.

The technology, called a chromatin array, was developed by researchers at UT Southwestern Medical Center at Dallas and is described in the July issue of the journal Genome Research.

DNA, which contains the genetic instructions needed to make a human or any other life form, is a long molecule that is tightly compacted in a cell’s nucleus. Various pieces of DNA are constantly being compressed and expanded like the folds of an accordion as a cell responds to its changing needs.



When the DNA relaxes, or expands, proteins called transcription factors gain access to the genetic code to "read" its instructions for making a molecule called RNA, which in turn makes other proteins that carry out life’s essential functions, from immune response and muscle contraction to cholesterol and hormone regulation.

When DNA is highly compacted, like a closed accordion, it’s not as accessible to transcription proteins, and cannot make RNA, said Dr. Harold "Skip" Garner, professor of biochemistry and internal medicine at UT Southwestern and senior author of the study.

Using the chromatin array, UT Southwestern researchers can detect the relative compactness of several stretches of DNA at a time with very high resolution, allowing them to determine which genes have the propensity for making RNA. They found that for many genes, but not all, the more open the DNA is, the more RNA is produced.

"The interesting genes are the ones that don’t behave this way," Dr. Garner said.

Exactly what controls compaction and expansion of DNA is still under scientific debate. In their next set of experiments, Dr. Garner and his team will apply various drugs – such as those used in cancer therapy – to cells in order to understand if and how these drugs affect DNA compaction. Such studies might lead to therapies aimed at activating beneficial genes, or turning off faulty ones.

The researchers also will investigate whether certain compaction and expansion states might be indicative of cancer or other diseases.
"Our current study describes the platform technology necessary to try to understand larger questions," Dr. Garner said. "The next step will involve using the technique to look at different types of cancer cells to see whether this type of assay could be a diagnostic tool."

Other techniques have be used to examine the compactness of DNA, but only a small piece of DNA at a time, said Ryan Weil, a UT Southwestern biophysics graduate student and the study’s lead author. "One of the advantages of our array is that it sorts through lots of pieces of DNA and gives us information about each segment all at once."

Currently, scientists determine which genes are turned on, or expressed, in a cell by extracting RNA and measuring how much of it is being produced for each gene. An RNA microarray, or "gene chip," is the standard equipment used to measure RNA expression levels.
"Only a small fraction of genes are making sufficient RNA to be detected with RNA microarrays," said Dr. Garner. "Many of the genes that make very small quantities of RNA are nonetheless very important, but they fall below the threshold of detection for current techniques."

The UT Southwestern technique allows researchers to study genes that previously weren’t accessible because there was not enough RNA to make a measurement of their activity.

"We can get information on a much larger number of genes, and whether or not they are in a state in which they can make RNA, using this technique than by using traditional RNA microarrays," Dr. Garner said. "This technology can tell us not only whether the DNA for a given gene is present or not, but also whether it is compacted or expanded and therefore ready to make RNA."

Mr. Weil said, "We can tell not just what cells are doing now, but what they could do in the future."

Amanda Siegfried | EurekAlert!
Further information:
http://www.utsouthwestern.edu

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Chances to treat childhood dementia

24.07.2017 | Health and Medicine

Improved Performance thanks to Reduced Weight

24.07.2017 | Automotive Engineering

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>