Complete characterisation of the American grass carp reovirus genome (genus Aquareovirus: family Reoviridae) reveals an evolutionary link between aquareoviruses and coltiviruses.
An aquareovirus was isolated from several fish species in the USA (including healthy golden shiners) that is not closely related to members of species Aquareovirus A, B and C. The virus, which is atypical (does not cause syncytia in cell cultures at neutral pH), was implicated in a winter die-off of grass carp fingerlings and has therefore been called 'American grass carp reovirus' (AGCRV). Complete nucleotide sequence analysis of the AGCRV genome and comparisons to the other aquareoviruses showed that it is closely related to golden ide reovirus (GIRV) (>92% amino acid [aa] identity in VP5(NTPase) and VP2(Pol)). However, comparisons with grass carp reovirus (Aquareovirus C) and chum salmon reovirus (Aquareovirus A) showed only 22% to 76% aa identity in different viral proteins. These findings have formed the basis for the recognition of AGCRV and GIRV as members of a new Aquareovirus species 'Aquareovirus G' by ICTV. Further sequence comparisons to other members of the family Reoviridae suggest that there has been an 'evolutionary jump,' involving a change in the number of genome segments, between the aquareoviruses (11 segments) and coltiviruses (12 segments). Segment 7 of AGRCV encodes two proteins, from two distinct ORFs, which are homologues of two Coltivirus proteins encoded by genome segments 9 and 12. A similar model has previously been reported for the rotaviruses and seadornaviruses.
Mohd Jaafar
Fauziah
F
Department of Arbovirology, Institute for Animal Health, Pirbright, Woking, Surrey, GU24 0NF, UK.
Goodwin
Andrew E
AE
Belhouchet
Mourad
M
Merry
Gwenn
G
Fang
Qin
Q
Cantaloube
Jean-François
JF
Biagini
Philippe
P
de Micco
Philippe
P
Mertens
Peter P C
PP
Attoui
Houssam
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002347:Carps / Q000821:virology*; D018162:Coltivirus / Q000145:classification* / Q000235:genetics*; D019143:Evolution, Molecular; D016679:Genome, Viral; D046529:Microscopy, Electron, Transmission; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D022661:RNA, Untranslated / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics; D012087:Reoviridae / Q000145:classification* / Q000235:genetics* / Q000648:ultrastructure; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014481:United States; D017361:Viral Nonstructural Proteins / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics
D022661:RNA, Untranslated; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins; D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase