Microviridae

Microvirus Spiromicrovirus Bdellomicrovirus Chlamydiamicrovirus

The Microviridae are a family of bacteriophages, including the following genera:
 * Genus Microvirus; type species: Enterobacteria phage φX174
 * Genus Spiromicrovirus; type species: Spiroplasma phage 4
 * Genus Bdellomicrovirus; type species: Bdellovibrio phage MAC1
 * Genus Chlamydiamicrovirus; type species: Chlamydia phage 1

Genome and Phylogenetics
Microviridae are icosahedral ssDNA bacteriophages. Their genome sizes range from 4.5-6kb and are circular in their conformation. The genome is housed within a tailless icosahedral virion particle. The microviridae can be defined into three main clades according to genome sizes and these are assigned according to their similarity to known lab based strains – the X174-like clade, G4-like clade and the  3-like clade. The X174-like clade of microviridae have the smallest and least variable genomes (5,386-5,387bp). The G4-like clade varies in genome size from 5,486-5,487bp while the largest genome sized group was the 3-like clade, their genomes ranging in size from 6,061-6259bp. The size variability within the groups mainly occurs as a result of insertions and deletions of the intergenic regions.