Aposematic coloration, commonly observed in noxious organisms, serves as a warning to predators to avoid attacking specific prey. This coloration is conspicuous in nature, with one of the most common examples being a red and black pattern. The plant Abrus precatorius exhibits this warning signal in its seeds, which resemble lady beetles and contain the concentrated toxin abrin. Aphelocoma coerulescens, an endemic and federally threatened bird in the state of Florida, shares a similar distribution with A. precatorius, making interaction between the two species possible. Using an edible model of the Abrus seed, this potential interaction was tested in Martin and Palm Beach County populations of A. coerulescens by presenting a red and white seed to individual scrub jays to determine whether they showed a preference for or avoidance of the red model seed. Results showed a significant tendency by the birds to prefer white over red, indicating that the color, independent of other warning signals, may function aposematically to discourage predation of A. precatorius seeds.

Reports of declining and deformed amphibians have been increasing in the last few years and this issue has become an important environmental problem of the last decade. This problem involves various infectious pathogens, including chytrid fungi and parasitic flatworms (trematodes). A possible explanation for increased incidence of amphibian declines is that something in the environment is affecting amphibian immune systems. Atrazine is the most widely used herbicide in North America and has been detected as a common environmental pollutant. The purpose of this research was to test the idea that low concentrations of atrazine may have an effect on the immune systems of amphibians, rendering them more susceptible to pathogen infection by using hemolytic plaque assays and hemocytometer counts. Rana pipiens showed a statistically significant difference in the number of plaques produced after 1 month of atrazine treatment but did not show statistically significant differences in treatments after 2 months of atrazine exposure. These results suggest that the immune system of frogs may be negatively affected by at least short term atrazine exposure.

Metalloproteases comprise a diverse superfamily of proteases with a requirement for a metal ion in their catalytic site. These proteins have been shown to play a role in many biological processes including fertilization, cellular adhesion, development, neurogenesis, and metastasis. To help elucidate the molecular mechanisms of metalloprotease function, a strategy was developed to detect and characterize metalloprotease activity in protein extracts prepared from the nematode Caenorhabditis elegans. Extensive biological characterization of C. elegans as well as the availability of the complete genome sequence makes this an excellent model system to study the functions of gene products. Metalloprotease activity was detected in protein extracts prepared from C. elegans assayed in the presence of the fluorescent metalloprotease substrate 2-aminobenzoyl-Ala-Gly-Leu-Ala-4 nitrobenzylamide (AAGLAN). The specificity of this metalloprotease activity was characterized using the inhibitory compounds Phenantrolin (30 mM), a metal chelator, and Phosphoramidon (100 μM), a specific inhibitor, which reduced metalloprotease activity in these extracts 96% and 59% respectively. Characterization of this metalloprotease activity may help to elucidate the role of these proteins in fundamental biological processes and abnormal disease conditions in C. elegans. Multiple sequence alignments of the C. elegans astacin, matrixin, and reprolysin metalloproteases revealed highly conserved metal binding and catalytic domains. Phylogenetic trees of these nematode metalloproteases revealed multiple major subfamilies, whose members likely contribute to the enzyme activity detected. These experiments provide a link to couple biochemical and pharmacological characterization with the genetics and biology of metalloproteases in C. elegans and may help to elucidate their biological functions.