Larger iridoviruses break down into larger but morphologically similar subunits. Genome Iridoviruses contain a single copy linear dsDNA genome that ranges in size from 150 to 280 kbp depending on viral species. The genomes appear unique within the eucaryotic viruses in that they are terminally redundant and cyclically permuted. A simplistic view of terminal redundancy and cyclic permutation. This genomic structure has been found in all iridoviruses so far studied.
Subtle variations do occur between different genera in the cyclic permutation.
Plasmid rescue experiments identified six origins of replication in CIV, a feature consistent with cyclic permutation. Three of these origins have been sequenced and all were predicted to form hairpin structures. The replication of iridoviruses comes mainly from studies of FV3 and this has become the model for iridovirus replication. Although packaging occurs in the cytoplasm of infected cells, a nuclear stage is also present. Virus particles enter the cell by pinocytosis and uncoating occurs.