Linking genetic and environmental factors in amphibian disease risk. (27th May 2015)

• Record Type: Journal Article
• Authors: Savage, Anna E.; Becker, Carlos G.; Zamudio, Kelly R.
• Is Part Of: Evolutionary applications. Volume 8:Number 6(2015)
• Page Start: 560
• Page End: 572
• Publication Date: 2015-05-27
• Subjects: Evolution (Biology) -- Periodicals; Genetics -- Periodicals; Natural selection -- Periodicals; Ecology -- Periodicals; 576.8
• DOI: 10.1111/eva.12264
• Languages: English
• ISSNs: 1752-4571

Abstract

<abstract abstract-type="main" id="eva12264-abs-0001"> <title>Abstract</title> <p>A central question in evolutionary biology is how interactions between organisms and the environment shape genetic differentiation. The pathogen <italic>Batrachochytrium dendrobatidis</italic> (<italic>Bd</italic>) has caused variable population declines in the lowland leopard frog (<italic>Lithobates yavapaiensis</italic>); thus, disease has potentially shaped, or been shaped by, host genetic diversity. Environmental factors can also influence both amphibian immunity and <italic>Bd</italic> virulence, confounding our ability to assess the genetic effects on disease dynamics. Here, we used genetics, pathogen dynamics, and environmental data to characterize <italic>L. yavapaiensis</italic> populations, estimate migration, and determine relative contributions of genetic and environmental factors in predicting <italic>Bd</italic> dynamics. We found that the two uninfected populations belonged to a single genetic deme, whereas each infected population was genetically unique. We detected an outlier locus that deviated from neutral expectations and was significantly correlated with mortality within populations. Across populations, only environmental variables predicted infection intensity, whereas environment and genetics predicted infection prevalence, and genetic diversity alone predicted mortality. At one locality with geothermally elevated water temperatures, migration estimates revealed source–sink dynamics that have likely prevented local adaptation. We conclude that integrating genetic and environmental variation among populations provides a better understanding of <italic>Bd</italic> spatial epidemiology, generating more effective conservation management strategies for mitigating amphibian declines.</p> </abstract>