Whole-Genome Analysis of a Novel Fish Reovirus (MsReV) Discloses Aquareovirus Genomic Structure Relationship with Host in Saline Environments

Abstract

Aquareoviruses are serious pathogens of aquatic animals. Here, genome characterization and functional gene analysis of a novel aquareovirus, largemouth bass Micropterus salmoides reovirus (MsReV), was described. It comprises 11 dsRNA segments (S1–S11) covering 24,024 bp, and encodes 12 putative proteins including the inclusion forming-related protein NS87 and the fusion-associated small transmembrane (FAST) protein NS22. The function of NS22 was confirmed by expression in fish cells. Subsequently, MsReV was compared with two representative aquareoviruses, saltwater fish turbot Scophthalmus maximus reovirus (SMReV) and freshwater fish grass carp reovirus strain 109 (GCReV-109). MsReV NS87 and NS22 genes have the same structure and function with those of SMReV, whereas GCReV-109 is either missing the coiled-coil region in NS79 or the gene-encoding NS22. Significant similarities are also revealed among equivalent genome segments between MsReV and SMReV, but a difference is found between MsReV and GCReV-109. Furthermore, phylogenetic analysis showed that 13 aquareoviruses could be divided into freshwater and saline environments subgroups, and MsReV was closely related to SMReV in saline environments. Consequently, these viruses from hosts in saline environments have more genomic structural similarities than the viruses from hosts in freshwater. This is the first study of the relationships between aquareovirus genomic structure and their host environments.

Two hepcidins from spotted scat (Scatophagus argus) possess antibacterial and antiviral functions in vitro

“…GCF and EPC cells were grown in medium 199 (Invitrogen, Carlsbad, CA) supplemented with 10% fetal calf serum at 25 C and 20 C, respectively. The preparation of virus stocks of SCRV and MsReV was performed as described previously [28,30].…”

“…SCRV is an enveloped single-stranded RNA (ssRNA) virus with a typical bullet shape [28,29]. MsReV is a non-enveloped double-stranded RNA (dsRNA) virus, infection by which leads to a typical cytopathic effect (CPE) characterized by cellecell fusion and syncytium formation [30]. Epithelioma papulosum cyprini (EPC) cells and grass carp fin (GCF) cells are susceptible to infection by SCRV and MsReV [28e30]; therefore EPC and GCF cell lines are useful for studies of the antiviral functions of fish AMPs against SCRV and MsReV.…”

Isolation and characterization of the fall Chinook aquareovirus

“…Interferon induction by aquareoviruses has shown to be a potential protective mechanism against other more pathogenic viruses such as IHNV [ 7 ]. Future studies will also be required to understand the geographical and temporal breadth and evolution of fall Chinook aquareovirus, and whether it has pathogenicity in other fish species [ 8 ].…”

“…The reliance on molecular detection necessitates the availability of complete genome sequences to improve PCR primer design and diagnostic test accuracy and to understand virus diversity and their molecular evolution. Aquareoviruses all contain 11 dsRNA segments that encode for seven structural proteins (VP1-VP7) and 5 nonstructural proteins [ 2 , 8 ]. While their distribution among the seven aquareovirus species is uneven, approximately 15 aquareovirus genomes have been completed and several strains have been partially completed [ 2 ].…”

Real-Time Dissecting the Entry and Intracellular Dynamics of Single Reovirus Particle

“…World aquaculture is the fastest growing food-producing sector in the world (Cressey, 2009 ), which greatly contributes to food security and poverty alleviation (Naylor et al, 2000 ; Tilman and Clark, 2014 ; Costello et al, 2016 ; Fisheries, 2016 ). Over the last decade, more and more aquareoviruses have been isolated and completely sequenced (>16 strains) in worldwide, such as Scophthalmus maximus reovirus (SMReV) and grass carp reovirus 109 strain (Ke et al, 2011 ; Chen et al, 2015 ; Zhang and Gui, 2015 ), posing a global threat to aquaculture.…”