Analysis of cytoskeletal and motility proteins in the sea urchin genome assembly.

The sea urchin embryo is a classical model system for studying the role of the cytoskeleton in such events as fertilization, mitosis, cleavage, cell migration and gastrulation. We have conducted an analysis of gene models derived from the Strongylocentrotus purpuratus genome assembly and have gathered strong evidence for the existence of multiple gene families encoding cytoskeletal proteins and their regulators in sea urchin. While many cytoskeletal genes have been cloned from sea urchin with sequences already existing in public databases, genome analysis reveals a significantly higher degree of diversity within certain gene families. Furthermore, genes are described corresponding to homologs of cytoskeletal proteins not previously documented in sea urchins. To illustrate the varying degree of sequence diversity that exists within cytoskeletal gene families, we conducted an analysis of genes encoding actins, specific actin-binding proteins, myosins, tubulins, kinesins, dyneins, specific microtubule-associated proteins, and intermediate filaments. We conducted ontological analysis of select genes to better understand the relatedness of urchin cytoskeletal genes to those of other deuterostomes. We analyzed developmental expression (EST) data to confirm the existence of select gene models and to understand their differential expression during various stages of early development.

Emission of chiral organochlorine pesticides from agricultural soils in the cornbelt region of the U.S.

Several organochlorine pesticides are chiral molecules manufactured as racemic mixtures. Past research has shown that selective degradation of pesticide enantiomers by microorganisms occurs resulting in nonracemic signatures in soils. In this work, volatilization of chiral pesticides from soil was investigated to determine if enantioselective breakdown in soils could be used as a source signature to track releases of chiral pesticides to the atmosphere. Air samples were taken directly above agricultural soils at several sites, and enantiomeric signatures were found to be nonracemic following patterns found in the soil. A follow up study at one site showed that for most compounds concentration decreased with increasing height above the soil, while enantiomer fractions for chiral pesticides were similar to that found in the soil, signifying the soil as a source to the air. The enantiomer fractions of ambient air samples from rural nonagricultural areas in the region were also found to be nonracemic.