Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Can genetic information be controlled by light?

13.10.2008
Researchers at Kiel University report sequence-dependent effects of light on DNA

DNA, the molecule that acts as the carrier of genetic information in all forms of life, is highly resistant against alteration by ultraviolet light, but understanding the mechanism for its photostability presents some puzzling problems.

A key aspect is the interaction between the four chemical bases that make up the DNA molecule. Researchers at Kiel University have succeeded in showing that DNA strands differ in their light sensitivity depending on their base sequences. Their results are reported by Nina Schwalb and colleagues in the current issue of the journal Science appearing on October 10, 2008.

It has been known for many years that the individual bases that code the genetic information contained in DNA show a high degree of photostability, as the energy that they take up from UV radiation is immediately released again. Surprisingly, however, it is found that in DNA, which consists of many bases, those mechanisms are ineffective or only partially effective. It seems that the deactivation of UV-excited DNA molecules must instead occur by some completely different mechanisms specific to DNA, which are not yet understood. Through measurements by a variety of methods on DNA molecules with different base sequences, the research group led by Professor Friedrich Temps at the Institute of Physical Chemistry of Kiel University has now been able to confirm and clarify that assumption.

According to Professor Temps, "DNA achieves its high degree of photostability through its complex double-helix structure. The interactions between bases that are stacked one above another within a DNA strand, and the hydrogen bonds between the base pairs of the two complementary single strands in the double-helix play key roles. Through the different interactions that we have observed the DNA acts to some extent as its own sun-protection".

Nina Schwalb investigated many different base combinations in synthetically-produced DNA molecules. Using a femtosecond pulsed laser spectroscope, she measured the characteristic energy release for each combination. She was able to measure the time for which the molecules continued to fluoresce, and thus how long they stored the light energy. She found that for some base combinations these fluorescence ‘lifetimes’ were only about 100 femtoseconds, whereas for others they were up to a thousand times longer. A femtosecond is one millionth of a billionth of a second.

Commenting on the conclusions from her research, Nina Schwalb says: “We have investigated the photophysical properties and have found that different base combinations have widely different fluorescence lifetimes. This could lead to the development of a new diagnostic method whereby laser light could be used to directly recognise certain genetic sequences without, for example, having to mark the DNA with dyes as in the method used at present".

One might also envisage linking the photophysical properties to genetic characteristics. When these mechanisms are better understood, it might in the long term become possible to repair gene mutations using laser radiation.

"In the field of nano-electronics it has already been shown that synthetically produced DNA can be used as ‘nano-wires’. On the basis of the different reaction times of the molecules it might one day become possible to use laser pulses to ‘switch’ specific molecules. It might even be possible under some circumstances to make transistors from DNA that would work through the hydrogen bonds," explains Professor Temps.

The work of Nina Schwalb is being supported by the German Research Foundation (DFG) as part of the project “Ultrafast Photodynamics of DNA".

Susanne Schuck | alfa
Further information:
http://www.uni-kiel.de
http://www.uni-kiel.de/aktuell/pm/2008/2008-092-photoresistenz-e.shtml

Further reports about: DNA DNA molecules Genetic Interaction LIGHT Laser Schwalb UV radiation genetic information hydrogen bonds

More articles from Life Sciences:

nachricht Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington

nachricht The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>