RNA Genetics: Volume I: RNA-Directed Virus Replication

RNA viruses are unique in having their information encoded in RNA. Their diversity, their widespread occurrence, and host range - rokaryotes, plants, and animals - eflect their evolutionary success. Even though RNA is generally believed to be the older form of information canier, RNA genomes are extremely rare in cellular organisms - RNA plasmids generally being regarded as inherited relics of viral infections - and so RNA replication does not occur in the normal processing of the genetic information. As a consequence, replication of viral RNA has several unique features.