For retroviruses in general ... in Cell 1 suggested that a triple-stranded cDNA intermediate of viral reverse transcription is required for nuclear translocation of viral cDNA.

RNA polymerases are sloppy. A retrovirus with an RNA genome, which is copied into DNA by a reverse transcriptase, is prone to mutations because the enzyme lacks the 3’ to 5’ proofreading capability of ...

How did viruses evolve? Are they a streamlined form of something that existed long ago, or an ultimate culmination of smaller genetic elements joined together?

Viral reverse transcriptase (RT) plays a critical role in replication (e.g., retroviruses, that reverse transcribe RNA templates into complementary DNA) and genome mutations (e.g., diversity ...