Topic: Conservation genomics of amphibians in French Guiana threatened by emerging pathogens
Dates: 1 October 2023 – 30 September 2026
Director: M. Chouteau
CBGP supervisor: C. Perrier
University : University of Guyane
Host laboratory: LEEISA, Cayenne
Amphibians are the most threatened group of terrestrial vertebrates in the world, facing increasing pressures at both local and global levels. The implementation of effective conservation strategies requires a thorough integration of knowledge on the biology and demography of species, as well as the ecosystems they inhabit. Among the emerging threats they face, infectious diseases such as chytridiomycosis represent a major danger.
In the Amazon rainforest of French Guiana, the fungus responsible for this disease, Batrachochytrium dendrobatidis, is regularly detected, infecting a wide range of species. Dendrobates tinctorius, a venomous poison dart frog endemic to the eastern Guiana Shield, is no exception. Recognised as a sentinel species for monitoring chytrid, D. tinctorius exhibits remarkably variable aposematic colouration, contributing to a high degree of phenotypic variation at an extremely fine geographical scale. This diversity provides a unique window into numerous evolutionary processes that remain the subject of scientific inquiry. Preserving these populations therefore appears essential, not only because of the intrinsic value represented by this remarkable biodiversity, but also to deepen our understanding of the evolutionary dynamics that shape the hyperdiverse life of the Neotropics.
The aim of this thesis is to draw on long-term monitoring of chytrid prevalence within D. tinctorius populations to understand the dynamics of this infection and the role of environmental factors. Genomic sequencing of 192 D. tinctorius individuals from across French Guiana will provide a better understanding of the genetic structure of this population, an essential component for ensuring the long-term conservation of this species. Finally, characterising the pathogen community present in different populations of this species using metagenomic tools will enable the identification of potential pathogens to be included in the amphibian biosurveillance strategy and the identification of factors determining the diversity of these communities. All these results will contribute to the development of robust, science-based conservation strategies to protect Neotropical amphibians from the growing threats they face.
