The Orthoretrovirinae (from Greek ὀρὀς “upright, correct”) form a subfamily within the virus family Retroviridae (retroviruses). Except for the genus Spumavirus, it includes all genera of the family. A distinguishing feature of this genus (and thus of the subfamily Spumaretrovirinae ) is the point in time during virus replication at which the viral RNA is transcribed into DNA using reverse transcriptase . In the case of orthoretroviruses, this happens at the very beginning of the virus replication, at the end of which a viral RNA is in turn packed into the virus particle (virion). In the case of spumaviruses, reverse transcription only becomes active during the assembly of the newly created virus particles at the end of replication, so that the viral genome is then packaged as double-stranded DNA.
ML Linial et al .: Subfamily Orthoretrovirinae . In: CM Fauquet, MA Mayo et al .: Eighth Report of the International Committee on Taxonomy of Viruses . London, San Diego, 2005 pp. 425-436 ISBN 0-12-249951-4
