Coevolution mechanisms that adapt viruses to genetic code variations implemented in their hosts

Abstract

Viruses, the preponderant species, are the agents of horizontal gene transfer between cellular organisms, a major means for generation of genetic variability that drives evolution in varying environments. Recent work on virus × host interaction has led to revision of the conventional idea that the genetic code of the virus and host must be same so that the host translational system facilitates efficient, accurate and complete expression of the infecting viral genome. There is evidence now that differences between the genetic codes of viruses and their hosts are not an absolute barrier to virus multiplication. The recent work on mechanisms by which viruses overcome the mismatch in codon usage of host versus theirs is discussed here contextually. Examples of coevolution of viruses and their hosts, in terms of genetic code usage, discussed here agree with the concept that their evolution is reciprocally driven and therefore suggestive of a kind of long-term interdependent symbiotic relationship between them.