title: Development of DNA mismatch repair gene, MutS, as a diagnostic marker for detection and phylogenetic analysis of algal Megaviruses.
abstract: Megaviruses are generically defined as giant viruses with genomes up to 1.26Mb that infect eukaryotic unicellular protists; they are clearly delineated in DNA polymerase B phylogenetic trees; in addition, common features often include an associated virophage observed during infection; the presence of an amino acyl tRNA synthetase gene; and a nucleic acid mismatch repair protein, MutS gene. The archetypal representative of this evolving putative family is Mimivirus, an opportunistic pathogen of Acanthamoeba spp. originally thought to be a bacterium until its genome sequence was published in 2004. Subsequent analysis of marine metagenomic data revealed Megaviruses are likely ubiquitous on the surface ocean. Analysis of genome sequences of giant viruses isolated from naturally occurring marine protists such as microalgae and a microflagellate grazer, started the expansion of the Megaviridae. Here, we explored the possibility of developing Megavirus specific markers for mutS that could be used in virus molecular ecology studies. MutS is split into 15 different clades representing a wide range of cellular life, and two that contain Megaviruses, clade MutS7 and clade MutS8. We developed specific PCR primers that recognized Megavirus clade MutS8, a clade that we propose discriminates most of the algal Megaviruses. Analysis of seawater off the coast of Maine, US, revealed novel groups of algal Megaviruses that were present in all samples tested. The Megavirus clade MutS8 marker should be considered as a tool to reveal new diversity and distribution of this enigmatic group of viruses.
authors: Bigelow Laboratory for Ocean Sciences, 60 Bigelow Drive, East Boothbay, ME 04544, USA; Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK. Electronic address: whw@pml.ac.uk.
authors: William H
authors: WH
authors: Wilson
authors: Bigelow Laboratory for Ocean Sciences, 60 Bigelow Drive, East Boothbay, ME 04544, USA.
authors: Ilana C
authors: IC
authors: Gilg
authors: Humboldt State University, Arcata, CA, USA.
authors: Amy
authors: A
authors: Duarte
authors: Bioinformatics Center, Institute for Chemical Research, Kyoto University, Uji, Kyoto, Japan.
authors: Hiroyuki
authors: H
authors: Ogata
mesh_terms: D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D005843:Geography; D008281:Maine; D008969:Molecular Sequence Data; D051719:MutS DNA Mismatch-Binding Protein / Q000235:genetics*; D017862:Phycodnaviridae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017434:Protein Structure, Tertiary; D012623:Seawater / Q000821:virology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D058009:Stramenopiles / Q000821:virology*; D014764:Viral Proteins / Q000235:genetics
chemical_list: D017931:DNA Primers; D004279:DNA, Viral; D005819:Genetic Markers; D014764:Viral Proteins; D051719:MutS DNA Mismatch-Binding Protein
keywords: Diagnostic marker; Megaviridae; Microalgae; Mismatch repair; MutS; Ocean