PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Bacteria's key innovation helps understand evolution

Genomic analysis of E. coli shows multiple steps to evolve new trait

Bacteria's key innovation helps understand evolution
2012-09-21
(Press-News.org) Several years ago researchers at Michigan State University (MSU) reported discovering a novel, evolutionary trait in a long-studied population of Escherichia coli, a rod-shaped bacterium commonly found in the lower intestine of mammals. The E. coli added a helping of citrate to its traditional diet of glucose, even though other E. coli can't consume citrate in the presence of oxygen.

These same biologists have now analyzed this new trait's genetic origins and found that in multiple cases, the evolving E. coli population needed more than one mutational step before the key innovation took hold. Complex traits, like using a new food source, are thought to be difficult and arise rarely, making the research of broad interest to both evolutionary biologists and public health scientists.

The findings, reported in this week's journal Nature, document the step-by-step process by which organisms evolve new functions. The study also highlights the importance of evolutionary changes that alter the physical arrangement of genes, leading to new patterns of gene regulation.

E. coli normally can't digest citrate when oxygen is present because they don't express the right protein to absorb citrate molecules. Citrate is a salt or class of citric acid commonly found in fruit such as lemons. So how did this mutation occur?

To find the answer, postdoctoral researcher Zachary Blount and MSU Hannah Distinguished Professor of Microbiology and Molecular Genetics Richard Lenski analyzed dozens of complete genome sequences from bacteria that had evolved this new trait and had been sampled and stored at different time points in the history of the lineage.

The National Science Foundation's Division of Environmental Biology partly funded the research, as did the NSF-supported BEACON Center for the Study of Evolution in Action.

The team used samples from Lenski's long-term E. coli experiment that started in February 1988 and has been ongoing for more than 24 years. The experiment allows Lenski and his students and colleagues to study more than 56,000 generations of bacterial evolution. In terms of generations, it is the longest running evolution experiment in history.

Twelve populations of E. coli live in an incubator in Lenski's laboratory producing about seven new generations every 24 hours. Each day, scientists take one percent of each population and transfer it into a new food source, a flask containing fresh glucose, which the bacteria readily eat, and citrate, which one population discovered how to eat after more than 30,000 generations. The researchers also take samples every 500 generations, and freeze them for later study.

Because they freeze the samples, when something new emerges the scientists can go back to earlier generations to look for the steps that happened along the way, which is what occurred in this case.

The researchers found that at least three mutations were required for the bacteria to effectively use citrate when oxygen is present. One or more mutations were necessary to set the physiological stage for the two later events. Then a critical gene duplication occurred that effectively re-wired the expression of a previously silent gene.

"These bacteria have evolved to consume a food resource--citrate--that no wild E. coli uses. Three mutations are required for this to happen, and they must occur in a specific order," said George Gilchrist, NSF program manager for the BEACON Science and Technology Center. "This study shows that the first mutation is required to set the stage for the next two, but surprisingly, this turns out to occur repeatedly and independently in different populations. What this suggests is that complex traits, at least in the microbial world, can evolve quickly and repeatedly."



INFORMATION:

Additional co-authors include Jeff Barrick, University of Texas and Carla Davidson, University of Calgary.

To learn more about this research, see the journal article in Nature magazine.


[Attachments] See images for this press release:
Bacteria's key innovation helps understand evolution

ELSE PRESS RELEASES FROM THIS DATE:

Denosumab reduces burden of giant-cell tumor of the bone

2012-09-21
PHILADELPHIA — Treatment with denosumab, a drug targeted against a protein that helps promote bone destruction, decreased the number of tumor giant cells in patients with giant-cell tumor of the bone, and increased new bone formation, according to the results of a phase II study published in Clinical Cancer Research, a journal of the American Association for Cancer Research. "Giant-cell tumor of the bone is a rare tumor that affects mostly young people," said Sant P. Chawla, M.D., director of the Santa Monica Oncology Center, Santa Monica, Calif. "Radical surgery is ...

Horticultural hijacking

Horticultural hijacking
2012-09-21
It's a battleground down there — in the soil where plants and bacteria dwell. Even though beneficial root bacteria come to the rescue when a plant is being attacked by pathogens, there's a dark side to the relationship between the plant and its white knight. According to research reported by a University of Delaware scientific team in the September online edition of Plant Physiology, the most highly cited plant journal, a power struggle ensues as the plant and the "good" bacteria vie over who will control the plant's immune system. "For the brief period when the beneficial ...

Virtual boundaries: How environmental cues affect motivation and task-oriented behavior

2012-09-21
NEW YORK - September 21, 2012 - Much of our daily lives are spent completing tasks that involve a degree of waiting, such as remaining on hold while scheduling a doctor's appointment or standing in line at an ATM. Faced with a wait, some people postpone, avoid, or abandon their task. Others endure the wait but feel dissatisfied and frustrated by the experience. Are there ways to improve our outlook and mindset while waiting? A new study shows that seemingly irrelevant environmental cues—such as queue guides, or barriers commonly used in banks and airports—can serve as ...

Historian uncovers rare writings by 18th century political icon

2012-09-21
Three political essays by one of the greatest British statesmen of the last 250 years have been discovered by a historian at Queen Mary, University of London. The new finds constitute the earliest political writings by Edmund Burke (1729-97), dating from around 1757, when he was 27-years-old, a period often described as the 'missing years' of his biography. Professor Richard Bourke, from the School of History at Queen Mary, came across the early essays among a series of notebooks belonging to William Burke, a close friend and distant relation of parliamentarian, Edmund. ...

Mount Sinai researchers identify predictors for inpatient pain

2012-09-21
Researchers from Mount Sinai School of Medicine have identified reliable predictors of pain by surveying patients throughout their hospital stays about the severity of their pain and their levels of satisfaction with how their pain was managed by hospital staff. Using this data, interdisciplinary teams treating patients were able to identify patients at higher risk for pain prior to, or immediately upon, their admission to the hospital, and create and implement intervention plans resulting in patients reporting lower levels of pain and higher levels of satisfaction with ...

Documenting women's experiences with chromosome abnormalities found in new prenatal test

2012-09-21
PHILADELPHIA – We often hear that "knowledge is power." But, that isn't always the case, especially when the knowledge pertains to the health of an unborn child, with murky implications, at best. A new study, led by researchers from the Perelman School of Medicine at the University of Pennsylvania, begins to document this exception to the general rule. Barbara Bernhardt, MS, CGC, a genetic counselor at the Hospital of the University of Pennsylvania, and colleagues contacted a small group of women who are participating in a larger Columbia University study investigating ...

Addictive properties of drug abuse may hold key to an HIV cure

2012-09-21
TALLAHASSEE, Fla. — A Florida State University researcher is on a mission to explore the gene-controlling effects of addictive drugs in pursuit of new HIV treatments. Working under the support of a $1.8 million grant from the National Institutes of Health (NIH), Florida State biologist Jonathan Dennis is studying a unique ability shared between a promising class of HIV treatments known as histone deacetylase inhibitors (HDIs) and psychostimulant drugs such as cocaine. "Current HIV treatments do just that — they treat the disease by preventing the spread of HIV in ...

How do we make moral judgments? Insights from Psychological Science

2012-09-21
New research published in Psychological Science, a journal of the Association for Psychological Science, provides intriguing insights into some of the factors that influence how we make moral judgments. Reappraising Our Emotions Allows Cooler Heads to Prevail We might like to think that our judgments are always well thought-out, but research suggests that our moral judgments are often based on intuition. Our emotions seem to drive our intuitions, giving us the gut feeling that something is 'right' or 'wrong.' In some cases, however, we seem to be able to override these ...

'Forest killer' plant study explores rapid environmental change factors

2012-09-21
TEMPE (Sept. 21, 2012) - It's called mile-a-minute weed or "forest killer." Mikania micrantha is an exotic, invasive species that spreads quickly, covering crops, smothering trees and rapidly altering the environment. Researchers at Arizona State University are spearheading a four-year research project that will explore what factors cause people and the environment to be vulnerable to rapid environmental change, such as an invasion by Mikania. Study findings likely will serve as a harbinger of the future as humans increasingly experience abrupt, extreme conditions associated ...

Study shows anaesthetic-related deaths reduced dramatically

2012-09-21
LONDON, ON – A team of researchers led by London's Dr. Daniel Bainbridge have compiled data from 87 studies worldwide that shows post-anaesthetic deaths have declined as much as 90 percent since before the 1970s. During the same period, the risk of dying from any cause within 48 hours of surgery has decreased by 88 percent. The study covered outcomes in both developed and developing countries, with the findings published in the current issue of the high-profile journal The Lancet. The study calls for use of evidence-based interventions to reduce the disparities between ...

LAST 30 PRESS RELEASES:

Pioneering neuroendocrinologist's century of discovery launches major scientific tribute series

Gendered bilingualism in post-colonial Korea

Structural safety monitoring of buildings with color variations

Bio-based fibers could pose greater threat to the environment than conventional plastics

Bacteria breakthrough could accelerate mosquito control schemes

Argonne to help drive AI revolution in astronomy with new institute led by Northwestern University

Medicaid funding for addiction treatment hasn’t curbed overdose deaths

UVA co-leads $2.9 million NIH investigation into where systems may fail people with disabilities

With the help of AI, UC Berkeley researchers confirm Hollywood is getting more diverse

Weight loss interventions associated with improvements in several symptoms of PCOS

Federal government may be overpaying for veterans’ health care in Medicare Advantage plans

Researchers awarded $2.5 million grant to increase lung cancer screenings in underserved communities

New trigger proposed for record-smashing 2022 Tonga eruption

Lupus Research Alliance announces Lupus Research Highlights at ACR Convergence 2024

Satellite imagery may help protect coastal forests from climate change

The secrets of baseball's magic mud

Toddlers understand concept of possibility

Small reductions to meat production in wealthier countries may help fight climate change, new analysis concludes

Scientists determine why some patients don’t respond well to wet macular degeneration treatment, show how new experimental drug can bridge gap

Did the world's best-preserved dinosaurs really die in 'Pompeii-type' events?

Not the usual suspects: Novel genetic basis of pest resistance to biotech crops

Jill Tarter to receive Inaugural Tarter Award for Innovation in the search for life beyond earth

Survey finds continued declines in HIV clinician workforce

Researchers home in on tumor vulnerabilities to improve odds of treating glioblastoma

Awareness of lung cancer screening remains low

Hospital COVID-19 burden and adverse event rates

NSF NOIRLab astronomers discover the fastest-feeding black hole in the early universe

Translational science reviews—a new JAMA review

How the keto diet could one day treat autoimmune disorders

Influence of tool corner radius on chip geometrical characteristics of machining Zr-based bulk metallic glass

[Press-News.org] Bacteria's key innovation helps understand evolution
Genomic analysis of E. coli shows multiple steps to evolve new trait