Transcriptome-Wide Comparisons and Virulence Gene Polymorphisms of Host-Associated Genotypes of the Cnidarian Parasite Ceratonova shasta in Salmonids

• Autores: Alama Bermejo, Gema; Meyer, Eli; Atkinson, Stephen D.; Holzer, Astrid S.; Wiśniewska, Monika M.; Kolísko, Martin; Bartholomew, Jerri
• Año de publicación: 2020
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: MYXOZOA; AQUACULTURE; CELL MIGRATION/MOTILITY; PROTEASES; SNPs
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Ceratonova shasta is an important myxozoan pathogen affecting the health of salmonid fishes in the Pacific Northwest of North America. Ceratonova shasta exists as a complex of host-specific genotypes, some with low to moderate virulence, and one that causes a profound, lethal infection in susceptible hosts. High throughput sequencing methods are powerful tools for discovering the genetic basis of these host/virulence differences, but deep sequencing of myxozoans has been challenging due to extremely fast molecular evolution of this group, yielding strongly divergent sequences that are difficult to identify, and unavoidable host contamination. We designed and optimized different bioinformatic pipelines to address these challenges. We obtained a unique set of comprehensive, host-free myxozoan RNA-seq data from C. shasta genotypes of varying virulence from different salmonid hosts. Analyses of transcriptome-wide genetic distances and maximum likelihood multigene phylogenies elucidated the evolutionary relationship between lineages and demonstrated the limited resolution of the established Internal Transcribed Spacer marker for C. shasta genotype identification, as this marker fails to differentiate between biologically distinct genotype II lineages from coho salmon and rainbow trout. We further analyzed the data sets based on polymorphisms in two gene groups related to virulence: cell migration and proteolytic enzymes including their inhibitors. The developed single-nucleotide polymorphism-calling pipeline identified polymorphisms between genotypes and demonstrated that variations in both motility and protease genes were associated with different levels of virulence of C. shasta in its salmonid hosts. The prospective use of proteolytic enzymes as promising candidates for targeted interventions against myxozoans in aquaculture is discussed. We developed host-free transcriptomes of a myxozoan model organism from strains that exhibited different degrees of virulence, as a unique source of data that will foster functional gene analyses and serve as a base for the development of potential therapeutics for efficient control of these parasites.
Fil: Alama Bermejo, Gema. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; Argentina. Academy of Sciences of the Czech Republic. Biology Centre. Institute of Parasitology; República Checa. State University of Oregon; Estados Unidos
Fil: Meyer, Eli. Oregon State University; Estados Unidos
Fil: Atkinson, Stephen D.. Oregon State University; Estados Unidos
Fil: Holzer, Astrid S.. Academy of Sciences of the Czech Republic. Biology Centre. Institute of Parasitology; República Checa
Fil: Wiśniewska, Monika M.. Academy of Sciences of the Czech Republic. Biology Centre. Institute of Parasitology; República Checa
Fil: Kolísko, Martin. Academy of Sciences of the Czech Republic. Biology Centre. Institute of Parasitology; República Checa. University of South Bohemia; República Checa
Fil: Bartholomew, Jerri. Oregon State University; Estados Unidos