Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers use multiphoton microscopy to watch chromosomes in action

26.09.2006
Feverish fruit fly larvae, warmed in a toasty lab chamber, are giving Cornell researchers a way to watch chromosomes in action and actually see how genes are expressed in living tissue.

Using multiphoton fluorescence microscopy, a technique pioneered at Cornell by physicist Watt W. Webb, researchers have for the first time been able to watch chromosomes change their form in order to activate their genes to synthesize key proteins in fruit fly cells. The advance could be a significant step toward understanding the basic processes that underlie gene expression.

The discovery was the result of cross-disciplinary collaboration between Webb and John Lis, Cornell's Barbara McClintock Professor of Molecular Biology and Genetics. Jie Yao, who recently earned his Ph.D. at Cornell, initiated and facilitated the work.

"This technology will revolutionize the way we see gene expression in organisms," said Lis. "We're watching transcription in real time in living cells."

... more about:
»HSF »Microscopy »chromosomes »multiphoton »watch

The research was described in the Aug. 31 issue of the journal Nature.

The team's experiments focused on gene regulatory mechanisms: specifically, what happens in a cell's nucleus when an external stimulus (heat) prompts specific genes to activate, and how those activated genes direct the production of proteins that protect the fly against the stress of heating.

"Whenever a cell is stressed -- bingo, it will produce proteins that will help the cell resist stress," said Webb, Cornell professor of applied physics and the S.B. Eckert Professor in Engineering. The process is triggered by a molecule called heat shock factor (HSF), which interacts with genes to cue the synthesis of new proteins. But this well-known process had never been seen in living cells.

Yao used multiphoton microscopy (MPM) to image living salivary gland tissue of Drosophila (fruit flies). Unlike other methods, which lack penetrating power and can damage the specimen, MPM delivers crisp, clear images, even in thicker tissue samples like Drosophila salivary glands.

The research was ultimately possible thanks to the unique composition of the fruit flies' polytene cells -- giant, multistranded chromosomes with hundreds of sets of the genome instead of the usual two sets in conventional cells. This enlarges the usual nuclear dimensions by about 10 times, making them large enough to image the detail.

The results were stunning. "Within two weeks we had spectacular pictures," said Lis. The images included pictures of the genes (hsp70 genes) that protect flies from the effects of extreme heat. By cranking up the heat, the researchers could activate these genes, and by using fruit flies specifically bred to carry fluorescent proteins on HSF, they could watch the transcription factors in action.

"This is the first time ever that anyone has been able to see in detail, at native genes in vivo, how a transcription factor is turned on, and how it then is activated," said Webb.

Using another method that Webb engineered at Cornell, called fluorescence recovery after photobleaching, the researchers also discovered that HSF activators bind to hsp70 genes much longer than previously thought before being replaced with new HSFs, which raises new questions about the mechanisms of gene transcription.

The technique also may offer a new tool for researchers across the biological sciences. Webb says it marks the success of an interdisciplinary trend that offers new potential for researchers in a variety of fields.

"Interaction between the physical sciences and the life sciences is very powerful," said Webb. "And it's becoming more powerful as a tool for advancing our understanding of the life sciences."

Better understanding transcription in lower organisms will help understand the processes in higher organisms, Yao added. "We hope to push the limits to human cells. That's the goal in the next 20 years."

Press Relations Office | EurekAlert!
Further information:
http://www.cornell.edu

Further reports about: HSF Microscopy chromosomes multiphoton watch

More articles from Life Sciences:

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>