Structural proteins translated from the mRNA are then used to package progeny -RNA and RDRP into virions. Most DNA viruses utilize a standard semi-conservative mode of replication. Often, the DNA is immediately transcribed by host proteins to produce mRNAs that encode virus-specific transcription factors. These factors lead to selective transcription of genes involved in DNA synthesis, and genes encoding additional transcription factors. This final set of factors produces mRNAs encoding structural proteins that enclose the newly-synthesized DNA, producing progeny virions.
Retroviruses have a unique means of replication.
RT then removes the RNA strand while synthesizing a new DNA strand to produce dsDNA, which then integrates into the host genome. From this location, progeny RNA molecules and structural proteins are combined to produce new viral particles. Abortive infections may result when a virus mistakenly infects a cell that does not permit viral replication. At the other extreme, cytolytic infections lead to cell lysis and release of large numbers of virus. Persistent infections may be productive, latent or transforming.