Cryptic infection of a broad taxonomic and geographic diversity of tadpoles by Perkinsea protists

摘要: The decline of amphibian populations, particularly frogs, is often cited as an example in support the claim that Earth undergoing its sixth mass extinction event. Amphibians seem to be sensitive emerging diseases (e.g., fungal and viral pathogens), yet diversity geographic distribution infectious agents are only starting investigated. Recent work has linked a previously undescribed protist with mass-mortality events United States, which infected frog tadpoles have abnormally enlarged yellowish liver filled cells presumed parasite. Phylogenetic analyses revealed this agent was affiliated Perkinsea: parasitic group within alveolates exemplified by Perkinsus sp., "marine" responsible for commercial shellfish populations. Using small subunit (SSU) ribosomal DNA (rDNA) sequencing, we developed targeted PCR protocol preferentially sampling clade Perkinsea. We tested on freshwater environmental DNA, revealing wide Perkinsea lineages these environments. Then, used same test Perkinsea-like livers 182 from multiple families frogs. identified distinct clade, encompassing low level SSU rDNA variation different lineage associated tadpole events. Members were present 38 sampled 14 genera/phylogroups, five countries across three continents. These data provide, our knowledge, first evidence protists infect taxonomic range frogs tropical temperate environments, including oceanic islands.