Scientific Publications

Novel, panzootic and hybrid genotypes of amphibian chytridiomycosis associated with the bullfrog trade.

Publication TypeJournal Article
AuthorsSchloegel, LM, Toledo LF, Longcore JE, Greenspan SE, Vieira CA, Lee M., Zhao S., Wangen C., Ferreira CM, Hipolito M., Davies AJ, Cuomo CA, Daszak P., and James TY
AbstractGlobal amphibian declines are linked with the presence of specific, highly virulent genotypes of the emerging fungal disease chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd) known as the global panzootic lineage (Bd-GPL). The global trade in amphibians for human consumption is suspected to have facilitated emergence of the disease, but evidence to support this is largely lacking. Here, we investigated the role the Lithobates catesbeianus (North American bullfrog) trade in spreading Bd genotypes by comparing strains associated with L. catesbeianus to a global panel using 36 sequenced loci from multiple chromosomal regions. Most bullfrogs were infected with Bd-GPL genotypes, but we also detected novel, highly divergent Bd genotypes (Bd-Brazil) from a live bullfrog in a US market and from native Brazilian anurans in the Atlantic Forest where bullfrogs are widely farmed. Sexual reproduction was also detected for the first time in Bd in the form of a hybrid genotype between the Bd-GPL and Bd-Brazil lineages in the Atlantic Forest. Despite the demonstration that ribosomal RNA types in Bd fail to undergo concerted evolution (over 20 sequence types may be found in a single strain), the Bd-GPL and Bd-Brazil lineages form largely separate clusters of related internal transcribed spacer (ITS) RNA sequences. Using ITS sequences, we then demonstrate the presence of Bd-Brazil in Japan, primarily on invasive L. catesbeianus. The finding that Bd is capable of sexual reproduction between panzootic and endemic genotypes emphasizes the risk of international wildlife trade as a source of additional Bd epizootics owing to hybridization.
Year of Publication2012
JournalMolecular ecology
Date Published (YYYY/MM/DD)2012/07/31
ISSN Number0962-1083
DOI10.1111/j.1365-294X.2012.05710.x
PubMedhttp://www.ncbi.nlm.nih.gov/pubmed/22857789?dopt=Abstract