Social cooperation is one of the most difficult adaptations for evolutionary biologists to explain because competition for resources inside the collective should lead to evolved traits that allow individuals to "cheat" the collective, win more resources and reproduce faster than their more cooperative neighbors -- thus undermining the social collective. In new research, evolutionary biologists and geneticists at Rice University and Baylor College of Medicine have isolated a genetic mechanism that counters competitive pressures and stabilizes cooperation. Their research appears in the Oct. 7 issue of the journal Nature.
Using the latest tools of molecular genetics, the researchers found that the phenomenon known as pleiotropy -- which occurs when a gene affects more than one inherited trait -- plays a crucial role in preventing "cheaters" from exploiting their neighbors within slime mold colonies that are formed by the social amoeba Dictyostelium discoideum. "What we’ve found is a molecular block to cheating and the genetic mechanism it relies on-- tying cooperative genes tightly with the essential function of reproduction," said paper co-author Joan Strassmann, professor of ecology and evolutionary biology at Rice. "Such a mechanism makes the loss of social genes costly to cheaters, and we believe this pleiotropic mechanism may be indicative of a general mechanism that’s employed in many species to stabilize cooperation."
The Rice-Baylor experiments draw upon one of the most extraordinary examples of social cooperation among microorganisms: when slime mold amoebae run out of the bacteria they eat, they group, then form a fruiting body in which about one-fifth of the single-celled individuals within the colony sacrifice themselves to form the stalk that holds up the spores. Before forming a stalk, the colony goes through a stage where it forms a slug-like structure. During this stage, cells produce a signaling molecule called DIF-1 that causes some members of the colony to differentiate themselves from the rest of the group and enter a prestalk stage of development. Using biotechnology, the research team created a mutant strain of Dictyostelium without the gene dimA, which codes for a key protein that Dictyostelium cells use to recognize DIF-1. "We wanted to see if cells without dimA could cheat the system by ignoring DIF-1 and thereby increase their chances of becoming spore cells rather than stalk cells," said paper co-author David Queller, professor of ecology and evolutionary biology at Rice. "We created colonies that contained roughly a 50-50 mix of our mutants and wild type strains of Dictyostelium, As expected, the dimA knockouts -- the cheaters -- were predisposed to move to the back of the slug, the position occupied by cells in the prespore stage of development."
Jade Boyd | EurekAlert!
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences