Family: Marnaviridae

Genus: Bacillarnavirus

Distinguishing features

Members of the genus form a separate clade from other members of the family upon phylogenetic analysis of RNA-directed RNA polymerase amino acid sequences. 

Virion

See discussion under family description. 

Genome organization and replication

The current members of the genus have di-cistronic genomes (Figure 2 Marnaviridae). See discussion under family description. 

Biology

See discussion under family description. 

Species demarcation criteria

Species demarcation cut-offs are based on pairwise comparisons of the RdRP and capsid amino acid sequences. The cut-offs are 90% identity for the RdRP and 75% identity for the capsid. The phylogenetic relationship of classified virus isolates and numerous unclassified viruses is shown in Figure 1 Bacillarnavirus. 

Figure 1 Bacillarnavirus.  Maximum likelihood tree of bacillarnavirus RdRP amino sequences. The tree was produced using the JTT model with a gamma distribution of frequencies and invariant sites. Bootstrap values are shown where they were over 70%. Tips are labelled with filled circles for members of species; open circles represent unclassified viruses. Heterosigma akashiwo RNA virus (AY337486) was used as an outgroup. This phylogenetic tree and corresponding sequence alignment are available to download from the Resources page.

Related, unclassified viruses

Virus names and virus abbreviations are not official ICTV designations.