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
Posted by Tim Sandle
