Data from: Diverse relationships between Batrachochytrium infections and antimicrobial peptide defenses across leopard frog populations

Synopsis Antimicrobial peptides (AMPs) play a fundamental role in the
innate defense against microbial pathogens, as well as other immune and
non-immune functions. Their role in amphibian skin defense against the
pathogenic fungus Batrachochytrium dendrobatidis (Bd) is exemplified by
experiments in which depletion of host’s stored AMPs increases mortality
from infection. Yet, the question remains whether there are generalizable
patterns of negative or positive correlations between stored AMP defenses
and the probability of infection or infection intensity across populations
and species. This study aims to expand on prior field studies of AMP
quantities and compositions by correlating stored defenses with an
estimated risk of Bd exposure (prevalence and mean infection intensity in
each survey) in five locations across the United States and a total of
three species. In all locations, known AMPs correlated with the ability of
recovered secretions to inhibit Bd in vitro. We found that stored AMP
defenses were generally unrelated to Bd infection except in one location
where the relative intensity of known AMPs was lower in secretions from
infected frogs. In all other locations, known AMP relative intensities
were higher in infected frogs. Stored peptide quantity was either
positively or negatively correlated with Bd exposure risk. Thus, future
experiments coupled with organismal modeling can elucidate whether Bd
infection affects secretion/synthesis and will provide insight into how to
interpret amphibian ecoimmunology studies of AMPs. We also demonstrate
that future AMP isolating and sequencing studies can focus efforts by
correlating mass spectrometry peaks to inhibitory capacity using linear
decomposition modeling.