Out in the cold and sick: low temperatures and fungal infections impair a frog's skin defenses

Amphibians worldwide continue to battle an emerging infectious disease, chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd). Southern leopard frogs, Rana sphenocephala, are known to become infected with this pathogen, yet they are considered 'of least concern' for declines due to chytridiomycosis. Previous studies have shown that R. sphenocephala secretes four antimicrobial peptides (AMPs) onto their skin which may play an important role in limiting susceptibility to chytridiomycosis. Here we examined the (1) effects of temperature and AMP depletion on infections with Bd and (2) effects of temperature and Bd infection on the capacity to secrete AMPs in juvenile leopard frogs. Pathogen burden and mortality were greater in frogs exposed to Bd at low temperature but did not increase following monthly AMP depletion. Both low temperature and Bd exposure reduced the capacity of juvenile frogs to restore peptides after monthly depletions. Frogs held at 14°C were poorly able to rest...,
Robak_et_al_data
The Robak_et_al_data.xlsx file contains data on survival, Bd load and antimicrobial peptide detection/relative intensity on separate tabs. On each tab, data are arranged by frogID and the treatment group of each frog (i.e., temperature, peptide treatment and pathogen exposure treatment combination) is indicated by three additional columns. For Bd load, only Bd-exposed frogs were assayed. For antimicrobial peptides, grayed rows indicate times when peptides were not collected (only mass was recorded).
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