Genus: Betaretrovirus
Subfamily: Orthoretrovirinae
Genus: Betaretrovirus
Distinguishing features
Virions can have “B-type” or “D-type” morphology, depending on the species. Genomes typically contain an additional regulatory gene that overlaps with the env gene and is encoded by a multiply-spliced mRNA – examples include the rem gene of MMTV and the rej gene of JSRV.
