Monday, 14 October 2013

New Organism Discovered

Researchers at the University of Arkansas have discovered and characterized a new organism that will help scientists understand the molecular mechanisms and ancestral genetic toolkit that enabled animals and fungi to evolve into diverse, multicellular life forms.

Jeffrey Silberman, a professor of biological sciences, isolated a new unicellular anaerobic eukaryote, and worked with former graduate student Matt Brown and others in the lab of Andrew Roger at Dalhousie University in Halifax, Nova Scotia, Cananda, on the genomics and description of this organism, which they named Pygsuia biforma. Brown, now a biology professor at Mississippi State University, is the lead author of the study, which was published August 28 in Proceedings of the Royal Society B (Biology).

To characterize the new organism, which was collected from brackish sediment in Prince Cove in Marstons Mills, Mass., the researchers described the morphology and sequenced the protein-coding genes of the organism to construct a 159-protein matrix for phylogenetic analyses. Phylogenetics is the study of the evolutionary relationships among groups of organisms. The researchers found that the organism resembled two types of a breviate, which is a unicellular eukaryote, but distinguished itself with its conspicuous, long flagella.

Most importantly, the phylogenetic tree established the organism as a distant but unequivocal relative to a "supergroup" of eukaryotes that include fungi and animals. It provides a glimpse of the various components of cell-to-cell adhesion, which is a requirement for multi-cellular organisms. The organism also possesses components of the integrin-mediated adhesion complex, which in animals plays a key role in cell-to-cell signaling and adhesion to the extracellular matrix.

The genus name for Pygsuia biforma is derived from part of the University of Arkansas Razorbacks sports cheer, "Wooo Pig Sooie," because it has a row of structures resembling the dorsal bristles of razorbacks, which are feral pigs. "Pyg" replaces "pig" as a play on the Latin Pygmae, a mythical race of pygmies, a reference to their small size, and "sui" replaces "sooie" for brevity and a reference to the animal family to which suids, the ancient biological family of pigs, belong. Consequently the genus name also means "little pig" in mock Latin. The species name, biforma, is derived from the presence two distinct cell forms that are observed in the life cycle.


A culture sample of Pygsuia biforma has been submitted to the Smithsonian Institution.

For further details, see:

M. W. Brown, S. C. Sharpe, J. D. Silberman, A. A. Heiss, B. F. Lang, A. G. B. Simpson, A. J. Roger. Phylogenomics demonstrates that breviate flagellates are related to opisthokonts and apusomonads. Proceedings of the Royal Society B: Biological Sciences, 2013; 280 (1769): 20131755 DOI: 10.1098/rspb.2013.1755

Posted by Tim Sandle