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Title: Amphibian‐killing chytrid in B razil comprises both locally endemic and globally expanding populations
Abstract

Chytridiomycosis, caused by the fungusBatrachochytrium dendrobatidis(Bd), is the emerging infectious disease implicated in recent population declines and extinctions of amphibian species worldwide.Bdstrains from regions of disease‐associated amphibian decline to date have all belonged to a single, hypervirulent clonal genotype (BdGPL). However, earlier studies in the Atlantic Forest of southeastern Brazil detected a novel, putatively enzootic lineage (Bd‐Brazil), and indicated hybridization betweenBdGPLandBd‐Brazil. Here, we characterize the spatial distribution and population history of these sympatric lineages in the Brazilian Atlantic Forest. To investigate the genetic structure ofBdin this region, we collected and genotypedBdstrains along a 2400‐km transect of the Atlantic Forest.Bd‐Brazil genotypes were restricted to a narrow geographic range in the southern Atlantic Forest, whileBdGPLstrains were widespread and largely geographically unstructured.Bdpopulation genetics in this region support the hypothesis that the recently discovered Brazilian lineage is enzootic in the Atlantic Forest of Brazil and thatBdGPLis a more recently expanded invasive. We collected additional hybrid isolates that demonstrate the recurrence of hybridization between panzootic and enzootic lineages, thereby confirming the existence of a hybrid zone in the Serra da Graciosa mountain range of Paraná State. Our field observations suggest thatBdGPLmay be more infective towards native Brazilian amphibians, and potentially more effective at dispersing across a fragmented landscape. We also provide further evidence of pathogen translocations mediated by the Brazilian ranaculture industry with implications for regulations and policies on global amphibian trade.

 
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NSF-PAR ID:
10246687
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
Molecular Ecology
Volume:
25
Issue:
13
ISSN:
0962-1083
Page Range / eLocation ID:
p. 2978-2996
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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