Meeting Abstract

S6.2  Wednesday, Jan. 5  Amphibian Immune Defenses against Chytridiomycosis: Impacts of Changing Environments ROLLINS-SMITH, L.A.*; RAMSEY, J.P.; REINERT, L.K.; WOODHAMS, D.C.; Vanderbilt University Medical Center, Nashville, TN; Vanderbilt University Medical Center, Nashville, TN; Vanderbilt University Medical Center, Nashville, TN; University of Zurich, Zurich, Switzerland louise.rollins-smith@vanderbilt.edu

Eco-immunology is the field of study that attempts to understand the functions of the immune system in the context of the host environment. Amphibians are currently suffering devastating declines and extinctions in nearly all parts of the world due to the emerging infectious disease, chytridiomycosis, caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd). This symposium presentation will review our current understanding of amphibian immune defenses against Bd and the effects of the disease at different life stages. We will review what is known about the impacts of temperature, environmental chemicals, and stress on host-pathogen interactions. Because chytridiomycosis is a skin infection and remains confined to the skin, immune defenses of the skin are critical for survival. Skin defenses include secreted antimicrobial peptides, secreted immunoglobulins, and antifungal metabolites produced by symbiotic skin bacteria. Cold temperatures, toxic chemicals, and stress inhibit the immune system and may impair natural defenses against Bd. Tadpole mouth parts can be infected by Bd, and this affects their growth. Newly metamorphosing frogs are especially vulnerable to the lethal effects of Bd because the immune system undergoes a dramatic reorganization at metamorphosis, and postmetamorphic defenses are not yet mature. Support: NSF IOS-0520847, IOS-0619536, and IOS-0843207.