Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Amoebae control cheating by keeping it in the family

09.07.2007
Study shows social amoeba's association with kin controls single-celled cheaters

No one likes a cheater, even a single-celled one.

New research from Rice University shows how cooperative single-celled amoebae rely on family ties to keep cheaters from undermining the health of their colonies. The research appeared in the Proceedings of the National Academy of Sciences in May.

"It's very unusual to get a complete story in biology -- one that marries careful field work with painstaking work in the laboratory -- and that's what we have here," said research co-author Joan Strassmann, chair of Rice's Department of Ecology and Evolutionary Biology.

Rice's research involved the common soil microbe Dictyostelium discoideum. These amoebae can be loners in times of plenty, but when food is scarce they work together, forming colonies to ensure their survival. About one fifth of the individuals in a colony form a tall, thin stalk. The rest climb the stalk and clump together into a bulbous fruiting body that can be carried away to better environs by the wind or on the legs of passing insects.

This simple social system poses an evolutionary conundrum for biologists; the members of the stalk give themselves up altruistically to support the colony, so what's to keep more selfish strains of D. discoideum from cheating the system, avoiding the stalk and out-reproducing their altruistic neighbors"

Strassmann and Rice evolutionary biologist David Queller have previously investigated how Dictyostelium colonies control cheating. For example, a study on D. discoideum showed that one gene governing cooperative behavior was also tied to reproduction. In another study, mutants that were genetically predisposed to avoid altruistic service in the stalk were also excluded from reproducing. A third study demonstrated that Dictyostelium purpureum preferentially associated with its own kin -- another mechanism that ensures altruism isn't taken advantage of by cheaters.

The current study combined graduate student Owen Gilbert's careful field and lab work on natural D. discoideum clones with exacting studies of genetically engineered mutant strains conducted by former postdoctoral researcher Kevin Foster and postdoctoral researcher Natasha Mehdiabadi.

"This work required investigators skilled in both field biology and molecular biology, an all-too-rare combination," Strassmann said.

Gilbert collected 144 D. discoideum fruiting bodies -- some of which were the first ever reported in the wild -- from 2003 to 2005 at the University of Virginia's Mountain Lake Biological Station in the Appalachian Mountains of southwestern Virginia. Back in the lab, Gilbert broke open the fruiting bodies and deciphered the genetic makeup of more than 3,000 individual spores. Though he found genetic differences between fruiting bodies, the spores within particular fruiting bodies were highly related.

Foster and Mehdiabadi worked with a mutant form of D. discoideum called "cheater A" that was missing a single gene known to play roles in both group productivity and reproduction. On their own, cheater A mutants produced few or no spores, but in mixed colonies they could thrive by cheating and avoiding service in the stalk. Foster and Mehdiabadi found cheater A spread readily within low-related colonies, and exacted a high toll by reducing the colonies' ability to reproduce. In colonies with highly related cells, the cheater's individual advantages were outweighed by the overall health of the group, so the cheaters couldn't gain a foothold.

"The combination of these two studies confirms something that's been long predicted by kin selection theory -- a mutant that cheats when relatedness is low cannot and has not spread in the wild because of natural relatedness," Queller said.

Gilbert said, "Our results answer the big question of why altruism persists. It persists because high relatedness prevents the spread of socially destructive mutants."

Jade Boyd | EurekAlert!
Further information:
http://www.rice.edu

More articles from Studies and Analyses:

nachricht WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf

nachricht First form of therapy for childhood dementia CLN2 developed
25.04.2018 | Universitätsklinikum Hamburg-Eppendorf

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal

22.05.2018 | Life Sciences

Asian tiger mosquito on the move

22.05.2018 | Life Sciences

Self-illuminating pixels for a new display generation

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>