title: New single-stranded DNA virus with a unique genomic structure that infects marine diatom Chaetoceros setoensis.
abstract: Diatoms are among the most abundant organisms in nature; however, their relationships with single-stranded DNA (ssDNA) viruses have not yet been defined in detail. We report the isolation and characterisation of a virus (CsetDNAV) that lytically infects the bloom-forming diatom Chaetoceros setoensis. The virion is 33 nm in diameter and accumulates in the nucleus of its host. CsetDNAV harbours a covalently closed-circular ssDNA genome comprising 5836 nucleotides and eight different short-complementary fragments (67-145 nucleotides), which have not been reported in other diatom viruses. Phylogenetic analysis based on the putative replicase-related protein showed that CsetDNAV was not included in the monophyly of the recently established genus Bacilladnavirus. This discovery of CsetDNAV, which harbours a genome with a structure that is unique among known viruses that infect diatoms, suggests that other such undiscovered viruses possess diverse genomic architectures.
authors.affiliation: National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tomaru
authors.forename: Kensuke
authors.initials: K
authors.lastname: Toyoda
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Suzuki
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Nagumo
authors.forename: Kei
authors.initials: K
authors.lastname: Kimura
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Takao
mesh_terms: D001483:Base Sequence; D004267:DNA Viruses / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D004270:DNA, Circular / Q000235:genetics; D004277:DNA, Single-Stranded / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics*; D017377:Diatoms / Q000821:virology*; D016679:Genome, Viral / Q000235:genetics*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics*; D019065:Virus Assembly / Q000502:physiology; D014779:Virus Replication / Q000502:physiology
chemical_list: D004270:DNA, Circular; D004277:DNA, Single-Stranded; D004279:DNA, Viral; D014764:Viral Proteins