Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study suggests ’noise’ in gene expression could aid bacterial pathogenicity

16.02.2006


Synthetic biology experiment turns up a previously unrecognized gene-expression phenomenon


A high level of variation in the amount of green fluorescence protein in individual non-growing E. coli cells surprised synthetic biology researchers at Boston University and the University of California, San Diego



An experiment designed to show how a usually innocuous bacterium regulates the expression of an unnecessary gene for green color has turned up a previously unrecognized phenomenon that could partially explain a feature of bacterial pathogenicity.

In a paper published in the Feb. 16 issue of Nature, researchers at Boston University (BU) and the University of California, San Diego (UCSD) reported that computer modeling predicted the new phenomenon before they confirmed it in laboratory experiments. The group led by James J. Collins, a biomedical engineering professor at BU, and Jeff Hasty, a bioengineering professor at UCSD, reported that the rise and fall in the amount of green-fluorescence protein in computer modeling matched the pattern recorded in E. coli cells grown in various laboratory conditions.


The researchers were surprised that cell-to-cell variation in the expression of the synthetic gene increased sharply as growth slowed and then stopped. "We were initially skeptical of our own results because they were so counterintuitive," said Collins. "But our laboratory experiments confirmed this increase in gene-expression variability, or noise, when growth stops. We think there may be some very interesting biology to explore in this situation."

Variability in gene expression could offer distinct survival advantages to a bacterium. Like a cruise ship whose life boats have been stocked with different combinations of food, first-aid kits, rain jackets, and flotation devices, a microscopic version of Survivor could occur in which only those individual bacterial cells with opportune combinations of proteins are able to weather harsh growth conditions in a pond or even inside a human body.

"This phenomenon could be relevant to bacterial ’persisters’ - dormant cells that are highly resistant to antibiotics," said Collins. "Many bacterial pathogens can generate these persisters, which over many months can become the source of chronic infections. We don’t understand the how persisters arise, but we think this unexpected gene-expression variability in bacterial cells is an interesting phenomenon that should be explored."

The group of researchers came up with the novel finding by using a relatively new research approach that involves the synthesis of simple gene networks, in this case one that produces a green-fluorescence protein. They measured expression of green fluorescence in a laboratory strain of E. coli under different growth conditions where other genes and proteins could potentially complicate the situation. They incorporated that information into a mathematical model.

The authors say their findings demonstrate the value of a so-called "bottom-up" approach to synthetic biology: models of relatively simple cellular processes can be used to predict the behavior of larger, more complex ones.

"We’re excited by this study because the model itself led to a counterintuitive prediction that was supported by experimentation," said UCSD’s Hasty. "The logical next step is to examine noise in the expression of proteins that would be essential to a bacterium’s survival," Hasty said. "We’ve only begun to get an inkling of how noise in gene expression may be involved in the life of a cell."

Rex Graham | EurekAlert!
Further information:
http://www.ucsd.edu

More articles from Life Sciences:

nachricht Molecular microscopy illuminates molecular motor motion
26.07.2017 | Penn State

nachricht New virus discovered in migratory bird in Rio Grande do Sul, Brazil
26.07.2017 | Fundação de Amparo à Pesquisa do Estado de São Paulo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

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

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>