Analysis of RNA editing in non-human primates

<p>Adenosine deaminases acting on RNA (ADAR) mediated RNA editing is the prevalent form of post-transcriptional RNA modification in higher organisms. Deaminated Adenosine creates Inosine, which is recognized as Guanosine thereby causing changes in the coding sequence, splicing and miRNA binding. RNA editing is mostly primate specific phenomenon and few studies of limited scope have shown that humans possess more editing sites than other primates.</p> <p>Here, we present the extent and intensity of RNA editing in non-human primates using a dataset where we analyze 21 polled tissues from 15 primate species/subspecies, spanning approximately 70 million years of primate evolution. Additionally, we analyze RNA editing in tissue specific manner, using data from 14 separate sequenced tissues from each of the species. Our results show that primates show less RNA editing than humans, with baboon, gorilla and chimp showing 19.7% 13.4% and 12.1% less editing sites respectfully, perfectly fitting within the phylogenetic tree.</p> <p>Expanding the analysis in tissue-specific manner, we observe distinct conservation of RNA editing sites throughout the different brain regions, with ones phylogenetically closest to human showing more human-like distributions. Additionally, we accessed the topology of the identified RNA editing sites in non-human primates, which revealed a surprising portion of the edited sites being in non-coding transcripts, thereby implicating a regulatory role. Further analysis of the editing sites in the coding regions of the transcripts show that edited codons are much more likely to be non-synonymous than synonymous (4:1 ratio), further more stressing the importance of RNA editing as regulatory mechanism.