NSF Fact Sheet

A slime-mold crowd of single-celled amoebas seems an unlikely place to look for the origins of complex social traits - especially altruism, where one individual risks itself for the benefit of an unrelated other. But, through an NSF Frontiers in Integrative Biological Research project, that's where David Queller and Joan Strassmann of Rice University and colleagues from the Baylor College of Medicine are looking, with good and complex reasons.

Biologically, cooperation, even sacrifice, among cells is more apparent in multi-cellular organisms, where cells have specific roles. For example, some transmit impulses, some pump gases, some produce the sperm or eggs that carry forth inherited characteristics, and some protect those that have the primary roles of reproduction.

But how do genetically unrelated single-celled amoebas distribute their roles when times get hard? When a slime mold faces starvation, unrelated amoebas form a fruiting body, shaped like a balloon on a string, with only those cells at the top able to form reproductive spores for dispersal, while others literally in supporting roles forego an opportunity to pass on their genes.

Using genetic technology and the sequenced genome, the FIBR group will seek to identify the genes and molecular pathways that underlie this form of social behavior among amoebas. The researchers will also examine the evolutionary costs of "cheating" (by clones whose cells avoid contributing to the sterile stalk).

Though mechanisms for social behavior in slime molds may not correspond closely to those in other organisms, this project is among the first to examine social evolution at such detail.

Lead principal investigators (Rice University):
David C. Queller, (713) 348-2656, queller@rice.edu
Joan E. Strassmann, (713) 348-4922, strassm@rice.edu

Participating institutions:
Rice University (Queller and Strassmann)
Baylor College of Medicine (Adam Kuspa, Gad Shaulsky, Chad A. Shaw)

Media contact at Rice: Jade Boyd, (713) 348-6778, jadeboyd@rice.edu

Total funding (est.), through August 2008: $5 million

Helpful web sites: http://www.ruf.rice.edu/~evolve http://www.ruf.rice.edu/~evolve/study.html#Dicty

Award abstract: https://www.fastlane.nsf.gov/servlet/showaward?award=0328455

The FIBR projects announced today include the following:

• "Integrated Ecological and Genomic Analysis of Speciation in Mimulus,"



• "Causes and Consequences of Recombination,"



• "Developmental Modeling and Informatics,"



• "Integrative Studies of Wolbachia-Eukaryotic Interactions: Genomes to Communities and Back,"



• "Do Species Matter in Microbial Communities?"

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The life cycle of the amoeba that creates a slime mold, and vice versa.
Illustration by Mary Wu and Rich Kessin, Columbia University.
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A collection of amoeba, stained red, aggregate to form a slime mold.
Photo by Kevin Foster of the Strassmann/Queller group, Rice University.
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From the fruiting body, which stands like a miniature street lamp, a slime mold will release reproductive spores.
Photo by Kevin Foster of the Strassmann/Queller group, Rice University.
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