Biologists are alarmed by the possibility of a new "silent spring". This time the birds will be singing, but many of the common frogs and toads (amphibians) may not be singing at night. The killer that has the potential to silence the frogs and toads is a fungus that invades the skin. Some amphibian species seem to be more resistant to the fungus due to their ability to secrete small protective proteins (antimicrobial peptides) onto the skin surface. This study will determine the amount of antimicrobial peptides made by healthy amphibians, the rate of restoration after the peptides are discharged onto the skin, and the time the peptides remain effective on the skin. Some experiments will test whether washing away or depleting the peptides will make the amphibians more susceptible to the fungus. The fungus, itself, could provoke a response from the frog to make more antimicrobial peptides, or the injury to the skin could result in production of less of the protective peptides. This study will measure whether peptide amounts increase or decrease after exposure to the fungus or to bacteria. Frogs and toads can be stressed due to crowding or other environmental changes including cold temperature. This study will determine how these natural stresses affect production of antimicrobial peptides and susceptibility to the fungus. Results may suggest better strategies for management of wildlife species to preserve them. It will train students in the field of immunology and conservation.
