Table 1

Characteristics of Mimivirus and CcBV and their genomes

Feature
Mimivirus
CcBV (in caterpillar host)
CcBV (in wasp host)

Genome size (base-pairs)
1,181,404
567,670
NK
Genome structure
Linear
30 closed circles
Provirus (linear)*
G + C composition (%)
28.0
33.95
NK
Coding density (%)
90.5
26.9
NK
Number of genes
1,262
156
NK
Genes containing introns
4
107
NK
Genes with assigned function
298
42
NK
Obligate intracellular parasite
Yes
Yes
No
Viral DNA replication in host
Yes
No
No*
Virion assembly in host
Yes
No
Yes
Transmission via virion
Yes
No
No*
Viral gene expression dependent on host cellular machinery
Yes
Yes
Yes

NK, not known; *circles are produced from amplified proviral DNA in female wasps at the time of egg laying, resulting in vertical transmission; genes contain self-splicing introns; CcBV is not pathogenic to the wasp host and exhibits a mutualistic association with it (see text for details).

Desjardins et al. Genome Biology 2005 6:212   doi:10.1186/gb-2005-6-3-212