Until the discovery of reverse transcriptase in 1970 (see 1.5 John Coffin — The Origin of Molecular Retrovirology), retroviruses were often referred to as C-type viruses, oncoviruses, oncornaviruses (onco+RNA), or RNA tumor viruses.
As of 2018 the family of retroviruses is categorized into two subfamilies encompassing all known genera and species of retroviruses:
- Retroviruses
- sub-family Orthoretrovirinae
- Alpharetroviruses:
- Avian leukosis virus (ALV, type species)
- Rous sarcoma virus (RSV)
- etc.
- Betaretroviruses:
- mouse mammary tumor virus (MMTV, type species)
- etc.
- Gammaretroviruses:
- murine leukemia virus (MLV, type species)
- feline leukemia virus (FeLV)
- gibbon ape leukemia virus (GaLV)
- etc.
- Deltaretroviruses:
- human T-lymphotropic viruses (HTLV types I–IV)
- simian T-lymphotropic viruses (STLVs types I–IV)
- bovine leukemia virus (BLV)
- Epsilonretroviruses:
- Walleye dermal sarcoma virus (type species)
- etc.
- Lentiviruses: Lentivirus (lente-, Latin for "slow") is a genus of retroviruses that cause chronic and deadly diseases characterized by long incubation periods. The lentiviruses include:
- HIV-1 (type species)
- HIV-2
- SIV simian immunodeficiency virus
- Visna-maedi virus
- equine infectious anemia virus (EIA)
- feline immunodeficiency virus (FIV)
- Alpharetroviruses:
- sub-family Spumavirinae or foamy viruses
- sub-family Orthoretrovirinae
See https://talk.ictvonline.org/taxonomy/ for more information.