Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanoscale microscope sheds first light on gene repair

14.11.2006
Proteins called H2AX act as "first aid" to DNA, among other roles. For the first time, scientists using the world's most powerful light microscope (the only one of its kind in the Americas) have seen how H2AX is distributed in the cell nucleus: in clusters, directing the first aid/repair after DNA injuries to the region where it is really needed.

Many biological processes lie out of the visual reach of scientists. The benefits of high-resolution electron microscopy are often offset by disruptive sample preparation requirements. Light microscopy allows easier sample prep and observations of living cells, but it has limited resolution. By manipulating how light waves behave, however, biophysicists are expanding the limits of light microscopy, and one of the latest advances--the 4Pi microscope--provides never-before-seen views of cellular components, including structures within the nucleus.

In a paper published in the Proceedings of the National Academy of Sciences, Joerg Bewersdorf of the Institute for Molecular Biophysics at The Jackson Laboratory, with collaborators Brian Bennett of the UMass Medical School and Leica Microsystems and Kendall Knight of the UMass Medical School, used the 4Pi microscope to examine the cellular response to a type of severe damage to the genetic material, DNA double-strand breaks. Such breaks provoke a rapid and highly coordinated series of events to identify and repair the damage. The response is critical, and there is an increased risk for cancer, developmental abnormalities and immunological problems when components of the repair processes are defective.

Traditional microbiological and genetics techniques can shed light on the molecular pathways of repair, but they don't address the astonishingly complex three-dimensional structure of the genetic material in the nucleus. 4Pi microscopy allows researchers to actually see the response in three dimensions, at resolutions down to 100 nm. Therefore, the role of the physical structures in various processes within the nucleus can now be visualized.

... more about:
»4Pi »Bewersdorf »DNA »H2AX »Microscopy »Nucleus »clusters

"The general application of these methods will provide unprecedented insights into cellular molecular events," said Bewersdorf. "This study represents a significant advance in our ability to visualize and quantify nuclear proteins in 3D."

Bewersdorf, Bennett and Knight examined a protein called H2AX, a kind of histone. Histones are structural proteins that act as spools around which DNA is wound, and they can also play roles in gene regulation and gene repair. H2AX is an early responder to DNA damage, and its change to what is known as gamma-H2AX is important for the coordination of signaling and repair activities. But it had not been known how H2AX is distributed throughout the nucleus or why its conversion to gamma-H2AX is limited to within a short distance of a break site. By using selective staining techniques and 4Pi visualization, Bewersdorf and colleagues determined that H2AX is distributed in distinct clusters uniformly throughout the nucleus and that the structure of these clusters may determine the boundaries of where gamma-H2AX spreads in response to a break.

"The clusters may provide a platform for the immediate and robust response observed following DNA damage," said Bewersdorf. "Moving forward, we will analyze the localization of the H2AX clusters relative to other nuclear components."

Joyce Peterson | EurekAlert!
Further information:
http://www.jax.org

Further reports about: 4Pi Bewersdorf DNA H2AX Microscopy Nucleus clusters

More articles from Life Sciences:

nachricht New catalyst controls activation of a carbon-hydrogen bond
21.11.2017 | Emory Health Sciences

nachricht The main switch
21.11.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>