Locus-specific gene expression pattern suggests a unique propagation strategy for a giant algal virus.
Emiliania huxleyi virus strain 86 is the largest algal virus sequenced to date and is unique among the Phycodnaviridae since its genome is predicted to contain six RNA polymerase subunit genes. We have used a virus microarray to profile the temporal transcription strategy of this unusual virus during infection. There are two distinct transcription phases to the infection process. The primary phase is dominated by a group of coding sequences (CDSs) expressed by 1 h postinfection that are localized to a subregion of the genome. The CDS of the primary group have no database homologues, and each is associated with a unique promoter element. The remainder of the CDSs are expressed in a secondary phase between 2 and 4 hours postinfection. Compartmentalized transcription of the two distinctive phases is discussed. We hypothesize that immediately after infection the nucleic acid of the virus targets the host nucleus, where primary-phase genes are transcribed by host RNA polymerase which recognizes the viral promoter. Secondary-phase transcription may then be conducted in the cytoplasm.
Allen
Michael J
MJ
Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, United Kingdom.
Forster
Thorsten
T
Schroeder
Declan C
DC
Hall
Matthew
M
Roy
Douglas
D
Ghazal
Peter
P
Wilson
William H
WH
D002467:Cell Nucleus / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D056890:Eukaryota / Q000821:virology*; D020869:Gene Expression Profiling; D015967:Gene Expression Regulation, Viral; D020411:Oligonucleotide Array Sequence Analysis; D017862:Phycodnaviridae / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication
D012367:RNA, Viral; D014764:Viral Proteins; D012321:DNA-Directed RNA Polymerases