Complete genome reconstruction and genetic analysis of Taura syndrome virus of shrimp from archival Davidson's-fixed paraffin embedded tissue.

Davidson's-fixed paraffin-embedded (DFPE) shrimp tissue are a priceless biological resource for pathogen discovery and evolutionary studies for aquaculture disease diagnostic laboratories worldwide. Nucleic acids extracted from DFPE tissues are often not adequate for most downstream molecular analysis due to fragmentation and chemical modifications. In this study, next generation sequencing (NGS) was used to reconstruct the complete genome of three geographical isolates (Belize, Venezuela and Hawaii) of a ~10 kb length RNA virus of shrimp, Taura syndrome virus (TSV), from DFPE tissues that have been archived for 15 years. Phylogenetic analyses showed that TSV isolates from Belize, Venezuela and Hawaii formed well supported clusters with homologous isolates from the corresponding regions submitted in the GenBank database. This is the first study to demonstrate the utility of archived tissue samples for identification of RNA viruses and evolutionary studies involving a viral disease in crustaceans and opens an avenue for expediting pathogen discovery.