Pseudogene rescue: an adaptive mechanism of codon reassignment

Johnson, L. J. ORCID: https://orcid.org/0000-0002-0006-1511 (2010) Pseudogene rescue: an adaptive mechanism of codon reassignment. Journal of Evolutionary Biology, 23 (8). pp. 1623-1630. ISSN 1010-061X doi: 10.1111/j.1420-9101.2010.02027.x

Abstract/Summary

Alterations to the genetic code – codon reassignments – have occurred many times in life’s history, despite the fact that genomes are coadapted to their genetic codes and therefore alterations are likely to be maladaptive. A potential mechanism for adaptive codon reassignment, which could trigger either a temporary period of codon ambiguity or a permanent genetic code change, is the reactivation of a pseudogene by a nonsense suppressor mutant transfer RNA. I examine the population genetics of each stage of this process and find that pseudogene rescue is plausible and also readily explains some features of extant variability in genetic codes.