Meeting Abstract
Chytrid fungus (Batrachochytrium dendrobatidis) is globally decimating amphibian populations by disrupting the long-term electrolyte transport gradient of skin tissue, thus hindering osmotic regulation and leading to cardiac arrest. Short term, livers of infected amphibian hosts show changes in gene expression just six days after fungal infection, yet it remains unclear how these changes influence the levels of pro- and anti-oxidant processes in these organisms. The present study utilized controlled, long term (6 week) laboratory infections of Cuban treefrogs (Osteopilus septentrionalis) with chytrid fungus in order to explore changes in enzymatic antioxidants and general measures of immune system robustness. We quantified the activity levels of catalase (CAT), a key antioxidant enzyme, in skeletal muscle and liver and used histological techniques to assess changes in densities of immune cells in spleen and liver. CAT activity generally decreased in skeletal muscle, but was increased in liver just 8 days into the six-week infection and remained elevated throughout. Further, granulocyte densities decreased in spleen, revealing a potential loss of overall immune system health following six weeks of infection. Together these preliminary data indicate that infection of amphibians with chytrid fungus results in physiological consequences that are tissue-specific, and also reveal that the activity of CAT is affected relatively quickly after initial exposure.
