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 Immune Defense Without Collateral Damage
24.01.2017 | Universität Basel

nachricht The interactome of infected neural cells reveals new therapeutic targets for Zika
23.01.2017 | D'Or Institute for Research and Education

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Efficient time synchronization of sensor networks by means of time series analysis

24.01.2017 | Information Technology

Immune Defense Without Collateral Damage

24.01.2017 | Life Sciences

Open, flexible assembly platform for optical systems

24.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>