Amphibian Hymenochirus boettgeri as an experimental model for infection studies with the chytrid fungus Batrachochytrium dendrobatidis

ABSTRACT

Model organisms are crucial in research as they can provide key insights applicable to other species. This study proposes the use of the amphibian species Hymenochirus boettgeri, widely available through the aquarium trade, as a model organism for the study of chytridiomycosis, a disease caused by the fungus Batrachochytrium dendrobatidis (Bd) and linked to amphibian decline and extinction globally. Currently, no model organisms are used in the study of chytridiomycosis, particularly because of the lack of availability and nonstandardized methods. Thus, laboratories around the world use wild local species to conduct Bd infection experiments, which prevents comparisons between studies and reduces reproducibility. Here, we performed a series of Bd infection assays that showed that H. boettgeri has a dose- and genotype-dependent response, can generalize previous findings on virulence estimates in other species, and can generate reproducible results in replicated experimental conditions. We also provided valuable information regarding H. boettgeri husbandry, including care, housing, reproduction, and heat treatment to eliminate previous Bd infections. Together, our results indicate that H. boettgeri is a powerful and low-ecological-impact system for studying Bd pathogenicity and virulence.

KEYWORDS:

• Model organism
• Hymenochirus boettgeri
• Batrachochytrium dendrobatidis
• virulence
• amphibians
• husbandry

Acknowledgements

We thank Diego Moura-Campos for helpful comments on an earlier version of this manuscript, Yi-Hong Ke for helping with the photographs, and Mia Sinks and Ana Felgner for helping with amphibian care. We are grateful to the members of U. Michigan Unit for Laboratory Animal Medicine for their advice and support in the development of our model, Dra Jill Keller, Kate Clifton, Allison Kulka, and Josh Kirk.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contribution

TC and TYJ conceptualized this study. TC, CS, RC, and EF conducted laboratory experiments. TC analysed the data and drafted the manuscript. All authors critically revised the manuscript.

Data availability statement

The data and full codes for all statistical tests are available at https://doi.org/10.5281/zenodo.8434900.

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/21505594.2023.2270252.

Additional information

Funding

This work was supported by the Gordon and Betty Moore Foundation Award [#9337] (10.37807/GBMF9337). TYJ is a Fellow in the CIFAR Program Fungal Kingdom: Threats and Opportunities. This work was partially supported by CIFAR and CIFAR fellowship catalyst grants.