text: Reverse transcriptases were discovered by Howard Temin at the University of Wisconsin–Madison in Rous sarcoma virions and independently isolated by David Baltimore in 1970 at MIT from two RNA tumour viruses: murine leukemia virus and again Rous sarcoma virus. For their achievements, they shared the 1975 Nobel Prize in Physiology or Medicine (with Renato Dulbecco).
  Well-studied reverse transcriptases include:
  * HIV-1 reverse transcriptase from human immunodeficiency virus type 1 () has two subunits, which have respective molecular weights of 66 and 51 kDas.
  * M-MLV reverse transcriptase from the Moloney murine leukemia virus is a single 75 kDa monomer.
  * AMV reverse transcriptase from the avian myeloblastosis virus also has two subunits, a 63 kDa subunit and a 95 kDa subunit.
  * Telomerase reverse transcriptase that maintains the telomeres of eukaryotic chromosomes.