Nontriplet feature of genetic code in <i>Euplotes</i> ciliates is a result of neutral evolution.

ABSTRACT: The triplet nature of the genetic code is considered a universal feature of known organisms. However, frequent stop codons at internal mRNA positions in Euplotes ciliates ultimately specify ribosomal frameshifting by one or two nucleotides depending on the context, thus posing a nontriplet feature of the genetic code of these organisms. Here, we sequenced transcriptomes of eight Euplotes species and assessed evolutionary patterns arising at frameshift sites. We show that frameshift sites are currently accumulating more rapidly by genetic drift than they are removed by weak selection. The time needed to reach the mutational equilibrium is several times longer than the age of Euplotes and is expected to occur after a several-fold increase in the frequency of frameshift s

SUBMITTER: Gaydukova SA 

PROVIDER: S-EPMC10235951 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature