Reverse transcription is not solely a retroviral mechanism. Animal hep
adnaviruses, plant caulimoviruses, and badnaviruses have a RNA interme
diate which is reverse transcribed into double-stranded DNA genome. Ba
sed on this fact, these three groups of viruses have been regrouped un
der the name of pararetroviruses. Although each one has developed its
own strategy to assure an efficient packaging of their genome, it is c
lear that they have adopted a strategy where encapsidation prepares fo
r initiation of reverse transcription. This is discussed in this revie
w. (C) 1995 Academic Press, Inc.