Corporate Banner
Satellite Banner
Scientific Community
Become a Member | Sign in
Home>News>This Article

Genetically Identical Bacteria Can Behave in Radically Different Ways

Published: Friday, January 03, 2014
Last Updated: Friday, January 03, 2014
Bookmark and Share
Although a population of bacteria may be genetically identical, individual bacteria within that population can act in radically different ways.

This phenomenon is crucial in the bacteria’s struggle for survival. The more diversity a population of bacteria has, the more likely it will contain individuals able to take advantage of a new opportunity or overcome a new threat, including the threat posed by an antibiotic.

In a recent study, researchers at the University of Washington showed that when a bacterial cell divides into two daughter cells there can be an uneven distribution of cellular organelles. The resulting cells can behave differently from each other, depending on which parts they received in the split.

“This is another way that cells within a population can diversify. Here we’ve shown it in a bacterium, but it probably is true for all cells, including human cells,” said Dr. Samuel Miller, UW professor of microbiology, genome sciences, and medicine and the paper’s senior author.

Bridget Kulasekara, who obtained a Ph.D in the UW Molecular and Cellular Biology Program, was the paper’s lead author. Other contributors included: Hemantha Kulasekara, Matthias Christen, and Cassie Kamischke, who work in Miller’s lab, and Paul Wiggins, UW assistant professor of physics and bioengineering. The paper appears in the online journal eLife.

In an earlier paper, Miller and his colleagues showed that when bacteria divided, the concentration of an important regulatory molecule, called cyclic diguanosine monophosphate (c-di-GMP). was unevenly distributed between the two progeny. c-di-GMP is a second messenger molecule. That finding was published in the journal Science in 2010.

Second messenger molecules transmit signals from sensors or receptors on the cell’s external membrane to targets within the cell, where they can rapidly alter a wide variety of cellular functions, such as metabolism and mobility. The ability to respond to external stimuli quickly is important for the bacteria’s survival. For instance, to stay alive, a bacterium must not  hesitate to  swim towards nutrients or away from toxins. This directional movement of microorganisms, spurred by the presence of a helpful or harmful substance, is known as chemotaxis.

“The effect of second messengers is almost immediate,” said Miller. “They allow bacteria to change their behavior within seconds.”

To detect the difference in c-di-GMP levels between cells, the researchers used a technique called Förster resonance energy transfer microscopy, or FRET microscopy. This allowed them to measure nanomolar changes of the concentration of c-di-GMP within individual bacteria as the changes happened second by second.

Different concentrations of c-di-GMP can have a profound influence on a cell’s behavior. For example, in the bacteria Pseudomonas aeruginosa, cells with high levels of c-di-GMP tend to remain still, adhere to surfaces and form colonies. Those with low levels, on the other hand, tend to actively swim about by using a corkscrew-shaped propeller located at one end of the bacterium.

In the latest study, the Miller and his colleagues worked out the molecular mechanism behind the difference in c-di-GMP concentrations seen between daughter cells.

When Pseudomonas cells divide, they pinch in half to create two daughter cells. Although the cells are genetically identical, only one daughter cell can inherit the bacterium’s single propeller. The other cell can synthesize its own propeller, but immediately after division the two cells are quite different.

What Miller and his coworkers report in the eLife paper is that the daughter cell that inherits the propeller also inherits an enzyme that is closely associated with the propeller that degrades c-di-GMP, as well as the organelle involved in directing  movement toward or away from stimuli that activates this enzyme.

Together these two organelles work in concert to lower the concentration of c-di-GMP and control swimming.

“What we have shown is that the uneven inheritance of organelles is another way cells have to create diversity and increase the chances of the survival of its species,” Miller said.

He added that his team’s findings may help explain how bacteria resist antibiotic treatments by always having some cells in their populations be in a slow-growing, resting state. Because antibiotics target fast-growing cells, these resting cells are more likely to survive the treatment. The findings might also help explain how some bacteria are able to adhere to and colonize surfaces such as urinary catheters, intravenous lines and heart valves.

In ongoing research, Miller’s team is trying to get a better understanding of the signals that can change second messenger concentrations very quickly and is screening compounds that could interfere with or alter those signals. Such compounds could be used to combat drug resistance, for instance, or inhibit a bacterium’s ability to adhere to surfaces and form slime-like colonies, called biofilms, that are highly resistant to antibiotics.

Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,800+ scientific posters on ePosters
  • More than 4,000+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

$12-Million Awarded to Study the Human Genome in 4-D
Project seeks to understand how a 6.5 feet of DNA folds to fit inside a cell.
Tuesday, October 20, 2015
Editing Genes to Create HIV Killers
Seattle scientists have managed to genetically transform human cells in the lab from HIV targets to HIV killers, and the technique could have implications for cancer and other diseases.
Monday, October 05, 2015
A New Single-Molecule Tool to Observe Enzymes at Work
A team of scientists at the University of Washington and the biotechnology company Illumina have created an innovative tool to directly detect the delicate, single-molecule interactions between DNA and enzymatic proteins.
Wednesday, September 30, 2015
Genetic Errors Linked To Aging Underlie Leukemia That Develops After Cancer Treatment
New research by Daniel Link, MD, and colleagues at The Genome Institute at Washington University has revealed that mutations that accumulate randomly as a person ages can play a role in a fatal form of leukemia that develops after treatment for another cancer.
Wednesday, December 10, 2014
Depletion of ‘Traitor’ Immune Cells Slows Cancer Growth in Mice
When a person has cancer, some of the cells in his or her body have changed and are growing uncontrollably.
Wednesday, September 25, 2013
Breakthrough in Detecting DNA Mutations Could Help Treat Tuberculosis and Cancer
The slightest variation in a sequence of DNA can have profound effects.
Tuesday, July 30, 2013
Extra Chromosome 21 Removed from Down Syndrome Cell Line
Scientists have succeeded in removing the extra copy of chromosome 21 in cell cultures derived from a person with Down syndrome, a condition in which the body’s cells contain three copies of chromosome 21.
Monday, November 12, 2012
Chemical Makes Blind Mice See
Researchers who discovered the chemical are working on an improved compound that may someday allow people with degenerative blindness to see again.
Wednesday, August 01, 2012
Exome Sequencing of Health Condition Extremes Can Reveal Susceptibility Genes
Comparing the DNA from patients at the best and worst extremes of a health condition can reveal genes for resistance and susceptibility.
Tuesday, July 17, 2012
Gene Therapy Delivered Once to Blood Vessel Wall Protects Against Atherosclerosis in Rabbit Studies By Leila Gray
The results came from research in rabbits, published July 19 in the journal Molecular Therapy.
Tuesday, July 26, 2011
Genetic Region Linked to a Five Times Higher Lung Cancer Risk
A narrow region on chromosome 15 contains genetic variations strongly associated with familial lung cancer, says a study conducted by scientists at Washington University.
Monday, September 22, 2008
Eight new Human Genome Projects Offer Large-Scale Picture of Genetic Differences among Individual
A nationwide consortium led by the University of Washington has completed the first sequence-based map of structural variations in the human genome.
Tuesday, May 06, 2008
Cancer Cells More Likely to Genetically Mutate
Researcher at University of Washington find that the cells who become cancerous can also become 100 times more likely to genetically mutate than regular cells.
Friday, February 23, 2007
Scientific News
Revolutionary Technologies Developed to Improve Outcomes for Lung Cancer Patients
Breath test to detect lung cancer brings oxygen directly to the wound.
Dementia Linked to Deficient DNA Repair
Mutant forms of breast cancer factor 1 (BRCA1) are associated with breast and ovarian cancers but according to new findings, in the brain the normal BRCA1 gene product may also be linked to Alzheimer’s disease.
New Gene Map Reveals Cancer’s Achilles’ Heel
Team of researchers switches off almost 18,000 genes
New Discovery Sheds Light on Disease Risk
Gaps between genes interact to influence the risk of acquiring disease.
Mathematical Model Helps Show How Zebrafish Get Their Stripes
The iconic yellow and blue stripes of zebrafish form dynamically as young fish develop and grow. A mathematical model developed by Brown University researchers helps to show how pigment cells interact to form the pattern.
Epigenome Influenced by Habitat and Lifestyle
Study on Pygmy hunter-gatherer populations and Bantu farmers in Central Africa shows that habitat and lifestyle can impact the epigenome.
Shining Light on Microbial Growth and Death Inside our Guts
Precise measurement of microbial populations in gastrointestinal tracts could be key to identifying novel therapies.
New Tech Vastly Improves CRISPR/Cas9 Accuracy
A new CRISPR/Cas9 technology developed by scientists at UMass Medical School is precise enough to surgically edit DNA at nearly any genomic location, while avoiding potentially harmful off-target changes typically seen in standard CRISPR gene editing techniques.
New Class of RNA Tumor Suppressors Identified
Two short, “housekeeping” RNA molecules block cancer growth by binding to an important cancer-associated protein called KRAS. More than a quarter of all human cancers are missing these RNAs.
Biologists Induce Flatworms to Grow Heads and Brains of Other Species
Findings shed light on role of a new kind of epigenetic signaling in evolution, could yield clues for understanding birth defects and regeneration.
Skyscraper Banner

SELECTBIO Market Reports
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,800+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,000+ scientific videos