Featured Research

from universities, journals, and other organizations

Engineered bacteria can make the ultimate sacrifice for the good of the population

Date:
November 20, 2012
Source:
EMBO - excellence in life sciences
Summary:
Scientists have engineered bacteria that are capable of sacrificing themselves for the good of the bacterial population. These altruistically inclined bacteria can be used to demonstrate the conditions where programmed cell death becomes a distinct advantage for the survival of the bacterial population.

Engineered bacteria can be used to demonstrate the conditions where programmed cell death becomes a distinct advantage for the survival of the bacterial population.
Credit: European Molecular Biology Organization

Scientists have engineered bacteria that are capable of sacrificing themselves for the good of the bacterial population. These altruistically inclined bacteria, which are described online in the journal Molecular Systems Biology, can be used to demonstrate the conditions where programmed cell death becomes a distinct advantage for the survival of the bacterial population.

"We have used a synthetic biology approach to explicitly measure and test the adaptive advantage of programmed bacterial cell death in Escherichia coli," said Lingchong You, senior author of the study and an associate professor at the Department of Biomedical Engineering, Duke University, and the Duke Institute for Genome Sciences & Policy. "The system is tunable which means that the extent of altruistic death in the bacterial population can be increased. We are therefore able to control the extent of programmed cell death as well as test the benefits of altruistic death under different conditions." The lead author of the study is Yu Tanouchi, a graduate student in the Department of Biomedical Engineering. Anand Pai and Nicolas Buchler also contributed to the work.

Scientists have known for some time that programmed cell death can be linked to the response of bacteria to stressful conditions, for example starvation of amino acids or the presence of competitor molecules. However, it is not clear why cells should choose to die under such conditions since it gives them no immediate advantages. Some researchers have suggested that programmed cell death allows cells to provide benefits to their survivors but until now it has been difficult to test this directly in experiments.

The researchers used synthetic biology procedures to engineer Escherichia coli in such a way that the bacterial cells are capable of suicidal behavior and promoting the good of the bacterial population. To do so they introduced a gene circuit, which consists of two modules, into the bacteria. If the "suicide module" is active it leads to the rupture and death of some bacterial cells when they are challenged with the antibiotic 6-aminopenicillanic acid. If the "public good" module is expressed, a modified form of the enzyme beta-lactamase is produced, which protects surviving cells from rupture or lysis by breaking down the antibiotic. This protection only occurs when the enzyme is released from inside the bacterial cells that make the ultimate sacrifice and die after rupture.

"Our results clearly demonstrate that it is possible to have conditions where the death of some bacteria confers an advantage for the overall population of bacteria," remarked You. "The optimal death rate for the bacterial population emerges after sufficient time has passed and is clearly visible in our system."

The scientists were also able to provide a possible explanation for the "Eagle effect," an unexpected phenomenon where bacteria appear to grow better when treated with higher antibiotic concentrations. "Overall our results fill in a conceptual gap in understanding the evolutionary dynamics of programmed bacterial death during stress and have implications for designing intervention strategies for effective treatment of bacterial infections with antibiotics," concluded You.


Story Source:

The above story is based on materials provided by EMBO - excellence in life sciences. Note: Materials may be edited for content and length.


Journal Reference:

  1. Naomi Habib, Ilan Wapinski, Hanah Margalit, Aviv Regev, Nir Friedman. A functional selection model explains evolutionary robustness despite plasticity in regulatory networks. Molecular Systems Biology, 2012; 8 DOI: 10.1038/msb.2012.50

Cite This Page:

EMBO - excellence in life sciences. "Engineered bacteria can make the ultimate sacrifice for the good of the population." ScienceDaily. ScienceDaily, 20 November 2012. <www.sciencedaily.com/releases/2012/11/121120121915.htm>.
EMBO - excellence in life sciences. (2012, November 20). Engineered bacteria can make the ultimate sacrifice for the good of the population. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2012/11/121120121915.htm
EMBO - excellence in life sciences. "Engineered bacteria can make the ultimate sacrifice for the good of the population." ScienceDaily. www.sciencedaily.com/releases/2012/11/121120121915.htm (accessed April 20, 2014).

Share This



More Plants & Animals News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Mich. Boy Unearths 10,000-Year-Old Mastodon Tooth

Mich. Boy Unearths 10,000-Year-Old Mastodon Tooth

Newsy (Apr. 20, 2014) A 9-year-old Michigan boy was exploring a creek when he came across a 10,000-year-old tooth from a prehistoric mastodon. Video provided by Newsy
Powered by NewsLook.com
Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
Powered by NewsLook.com
Man Claims He Found Loch Ness Monster With... Apple Maps?

Man Claims He Found Loch Ness Monster With... Apple Maps?

Newsy (Apr. 18, 2014) Andy Dixon showed the Daily Mail a screenshot of what he believes to be the mythical beast swimming just below the lake's surface. Video provided by Newsy
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins