Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tiny flies could lead to understanding potential for non-embryonic stem cells

01.03.2005


It has long been thought that cells that regenerate tissue do so by regressing to a developmentally younger state. Now two University of Washington researchers have demonstrated that cells can regenerate without becoming "younger."


Biologists for years have studied stem cells, the ones responsible for replenishing and regenerating an organism’s structures, aiming to find the means to selectively regenerate tissue such as that of the heart or liver in much the same way that the body heals a broken leg.

Much hope rests with non-embryonic stem cells, which can renew themselves and, within limits, produce all the specialized cell types from the type of tissue in which they originate. But scientists have puzzled over just how such cells function, how they can be spurred to create new tissue, and just when in their development it is determined what tissue they can produce.

Gerold Schubiger, a UW biology professor, and Anne Sustar, a research technician in his laboratory, used groups of cells, called imaginal discs, in fruit fly larvae to provide an easily controlled system to study regeneration. Imaginal discs convert genetic information that determines the specific tissue into which the cells will develop in the adult fly. For example, leg discs form only adult legs and wing discs form only adult wings. Normally, all of those cells develop into that specific tissue, either when the fly reaches the adult stage or when regenerating a lost structure, such as parts of a leg disc.



The exception is a very small number of cells in each disc, located at what the researchers term the "weak point." These cells change their ultimate destiny, or fate, as the disc regenerates tissue so that, for example, instead of regenerating leg structures they form wing structures. Such fate changes are known as transdetermination, and they demonstrate that a few cells have development potential that is adaptable rather than firmly fixed, Schubiger said. That has parallels in the adaptable development potential found in some vertebrate stem cells, he said.

In the case of the fruit flies, regeneration and transdetermination begin in the "weak point" of the leg imaginal disc when a signaling gene called wingless activates a selector gene called vestigial, which spurs wing development in that stem cell-like region. "In all organisms, selector genes activate or repress other genes that trigger production of different organs. Researchers studying cells with adaptable development potential want to know when, where and how those cells change their fate," Schubiger said.

In previous research involving vertebrates, he said, it was unclear whether cells involved in tissue regeneration had reverted to a younger state or were the same age as other cells in the organism. But he noted that it has been generally accepted that the regenerating cells revert to a younger state.

If that is true, those cells would have to divide faster than the others in the organism because younger cells divide faster than older cells. Sustar and Schubiger tested the theory in fruit flies, following the cells to see when and where the vestigial gene was activated. Since cells in the disc divide more slowly as they age, the researchers could see whether the cells involved in regeneration had reverted to a younger cycle. They found that neither cells involved in regeneration nor those that were changing their fate to become a different type of tissue had the characteristics, including the faster doubling time, of younger cells.

Sustar is the lead author of a paper describing the work, published in the Feb. 11 edition of the journal Cell. The work was supported by a grant from the National Institutes of Health.

Understanding the wingless gene’s function is key to understanding how stem cells can adapt their ultimate destiny, from leg tissue to wing tissue for example, Schubiger said.

There are many examples in which the wingless gene causes stem cells to change fates, he added. In hair follicle cells, for example, the wingless gene changes stem cells to skin cells. In a mouse, high levels of wingless genes change a specific group of lung cells into intestine cells.

"This work challenges old concepts of regeneration and has opened new avenues for stem cell research," Schubiger said. "This remarkable observation has not been reported in any stem cell research. We have set the stage to look at the cell cycle in other stem cell systems."

Vince Stricherz | EurekAlert!
Further information:
http://www.washington.edu

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 >>>