Cryptic species often go unrecognized in microorganisms because of a lack of sufficient knowledge of evolutionary units in these organisms. In some microorganisms, such as the social amoebae, kin recognition could play a useful role in determining where to draw species boundaries. To this end, I have been studying kin discrimination in the social amoeba Polysphondylium violaceum. P. violaceum has already been identified as a potential cryptic species, a group of species that are morphologically identical but reproductively isolated, through patterns of macrocyst formation (Clark, Francis and Eisenberg, 1973). I am looking at how different strains interact with each other, both within and between these groups.
P. violaceum is a social amoeba, like Dictyostelium discoideum, and like D. discoideum lives in soil unicellularly. When these cells start to starve, they aggregate into multicellular slugs and ultimately form multicellular fruiting bodies composed of dead vegetative stalk and viable spores. Because multicellularity occurs via aggregation and not through cell division, there is the opportunity for chimeric fruiting bodies to develop. In general, we should expect clones that are more closely related to form chimeric fruiting bodies more readily than more distantly related clones. By only associating with closely related clones, clones can gain indirect fitness benefits and may be able to limit the chance that they are cheated, forced into the stalk. I'm hopeful to extend this work to other dictyostelids in the near future.
I spent my undergraduate career working on wild strawberries (Fragaria virginiana). After obtaining my B.S. in Ecology and Evolution from the University of Pittsburgh, I spent 3 years as a research technician in a pathology lab, studying bone biology and pursuing my interest in the history and philosophy of science. I sorely missed studying evolution though, so in August 2000 I returned to that field by starting grad school in Joan and Dave’s lab at Rice.
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