Phylogenetic analysis of newly isolated grass carp reovirus

Abstract

Grass carp reovirus (GCRV) is a causative agent of haemorrhagic disease in grass carp that drastically affects grass carp aquaculture. Here we report a novel GCRV isolate isolated from sick grass carp that induces obvious cytopathic effect in CIK cells and name it as GCRV096. A large number of GCRV 096 viral particles were found in the infected CIK cells by electron microscope. The shape, size and the arrangement of this virus were similar to those of grass carp reovirus. With the primers designed according to GCRV 873 genome sequences, specific bands were amplified from sick grass carp and the infected CIK cells. The homology rates among vp4, vp6 and vp7 gene in GCRV 096 and those of some GCRV isolates were over 89%. In this study, the sequences of vp4, vp6 and vp7 were used to analyse sequence variation, phylogenetic relationships and genotypes in twenty five GCRV isolates. The results indicated these twenty five GCRV isolates should be attributed to four genotypes. And there were no obvious characteristics in the geographical distribution of GCRV genotype. The study should provide the exact foundation for developing more effective prevention strategies of grass carp haemorrhagic disease.

Insights into the Antiviral Immunity against Grass Carp (Ctenopharyngodon idella) Reovirus (GCRV) in Grass Carp

“…However, Pei et al classified GCRV-HZ08 into group I, GCRV-873 into group II, and HGDRV (GCRV104) into group III [ 14 ]. When AGCRV is introduced to the cluster, the GCRV strains are divided into four groups [ 15 ]. However, there is subtle difference of the phylogenetic relationships of GCRV when VP4, VP6, and VP7 are used for the clusters, respectively [ 15 ].…”

“…When AGCRV is introduced to the cluster, the GCRV strains are divided into four groups [ 15 ]. However, there is subtle difference of the phylogenetic relationships of GCRV when VP4, VP6, and VP7 are used for the clusters, respectively [ 15 ]. Although different people have different views on the cluster, one point that GCRV-873, GCRV-HZ08, and HGDRV are the representative strains of three different groups is consistent [ 8 , 14 , 15 ].…”

“…However, there is subtle difference of the phylogenetic relationships of GCRV when VP4, VP6, and VP7 are used for the clusters, respectively [ 15 ]. Although different people have different views on the cluster, one point that GCRV-873, GCRV-HZ08, and HGDRV are the representative strains of three different groups is consistent [ 8 , 14 , 15 ]. With the sequence distinctions among the strains, the cell culture characteristic, virulence, pathogenesis, and antigenicity of each strain are diverse.…”

“…As a novel fish reovirus, HGDRV can proliferate and induce significant apoptosis or CPE in CIK cells [ 13 , 20 ]. Similarly, GCRV096 can also cause the CPE in CIK when the cells are infected [ 15 ]. GCRV-873, the first strain isolated from hemorrhagic grass carp in China, can form CPE in CIK cells but lose the ability to infect grass carp [ 21 , 22 ].…”

Virus genomes and virus-host interactions in aquaculture animals

“…At least 15 reovirus genomes have been completely sequenced (Table 2). Of these, 11 reoviruses are different isolates from cultured grass carp obtained in various years and from different regions [85,[87][88][89][90][91][92]; the other four reoviruses were isolated from cultured golden shiner, chum salmon, Atlantic salmon (Piscine reovirus), and turbot (Scophthalmus maximus reovirus), respectively [93][94][95].…”