Hybrids of amphibian chytrid show high virulence in native hosts

Author(s)

Greenspan, S. E. ^[1] ; Lambertini, C. ^[2] ; Carvalho, T. ^[2] ; James, T. Y. ^[3] ; Toledo, L. F. ^[2] ; Haddad, C. F. B. ^{[4, 5]} ; Becker, C. G. ^[1]

Affiliation

^[1] Univ Alabama, Dept Biol Sci, Tuscaloosa, AL 35487 - USA

^[2] Univ Estadual Campinas, Dept Biol Anim, Lab Hist Nat Anfibios Brasileiros LaHNAB, BR-13083862 Campinas, SP - Brazil

^[3] Univ Michigan, Dept Ecol & Evolutionary Biol, Ann Arbor, MI 48109 - USA

^[4] Univ Estadual Paulista, Dept Zool, BR-13506900 Rio Claro, SP - Brazil

^[5] Univ Estadual Paulista, Aquaculture Ctr CAUNESP, BR-13506900 Rio Claro, SP - Brazil

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 8, JUN 25 2018.
• Web of Science Citations: 10

Abstract

Hybridization of parasites can generate new genotypes with high virulence. The fungal amphibian parasite Batrachochytrium dendrobatidis (Bd) hybridizes in Brazil's Atlantic Forest, a biodiversity hotspot where amphibian declines have been linked to Bd, but the virulence of hybrid genotypes in native hosts has never been tested. We compared the virulence (measured as host mortality and infection burden) of hybrid Bd genotypes to the parental lineages, the putatively hypovirulent lineage Bd-Brazil and the hypervirulent Global Pandemic Lineage (Bd-GPL), in a panel of native Brazilian hosts. In Brachycephalus ephippium, the hybrid exceeded the virulence (host mortality) of both parents, suggesting that novelty arising from hybridization of Bd is a conservation concern. In lschnocnema parva, host mortality in the hybrid treatment was intermediate between the parent treatments, suggesting that this species is more vulnerable to the aggressive phenotypes associated with Bd-GPL. Dendropsophus minutus showed low overall mortality, but infection burdens were higher in frogs treated with hybrid and Bd-GPL genotypes than with Bd-Brazil genotypes. Our experiment suggests that Bd hybrids have the potential to increase disease risk in native hosts. Continued surveillance is needed to track potential spread of hybrid genotypes and detect future genomic shifts in this dynamic disease system. (AU)

• FAPESP's process: 16/25358-3 - The chytrid fungus: from its origins to its consequences
• Grantee: Luis Felipe de Toledo Ramos Pereira
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/50741-7 - Diversity and conservation of Brazilian amphibians
• Grantee: Célio Fernando Baptista Haddad
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 11/51694-7 - Into the heart of an epidemic: a US-Brazil collaboration for integrative studies of the amphibian-killing fungus in Brazil
• Grantee: Luis Felipe de Toledo Ramos Pereira
• Support Opportunities: Regular Research Grants