DISSERTATION RESEARCH: Immunogenetics of Chytridiomycosis Resistance and Susceptibility in Rana yavapaiensis, a Declining North American Anuran

Cornell University, Ithaca NY

Investigators

Abstract

The emerging infectious disease chytridiomycosis has caused the decline or extinction of many amphibian species worldwide. The genetics of frog immunity will be critical to understanding the dynamics and potential outcome of this disease for amphibian biodiversity. This study investigates the genetic consequences of infection by the chytridiomycosis-causing pathogen Batrachochytrium dendrobatidis (Bd) in the lowland leopard frog, Rana yavapaiensis. The researchers propose to characterize disease prevalence across frog populations with different histories to determine the relationship between infection and disease, and to test for associations between chytridiomycosis susceptibility and frog genetic background in natural populations and in lab-reared individuals. Frog and Bd samples will be collected from genetically-distinct Arizona frog populations for five years, and tadpoles will be reared from five focal localities for experimental infections in the laboratory. Using each frog's infection and disease status along with genotypes at neutral (microsatellite) genetic markers and immunogenetic (major histocompatibility complex) genes, this study will test hypotheses about immunogenetics, disease susceptibility, and disease dynamics. Understanding the relationship between Bd infection and frog mortality, the importance of standing immunogenetic variation for population disease dynamics, and the effect of host genotype on disease outcome, will provide critical genetic indices for future studies of amphibian chytridiomycosis and other emerging wildlife diseases. One graduate student and several undergraduate students will receive broad training through participation in this project.