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 Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | 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: 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,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

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

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>