Evolutionary and ontogenetic changes in RNA editing in human, chimpanzee and macaque brains
we used RNA-Seq to quantify the RNA editing level at more than 8,000 previously annotated exonic A-to-I RNA editing sites in two brain regions - prefrontal cortex and cerebellum - of humans, chimpanzees and rhesus macaques. We observed substantial conservation of RNA editing levels between the brain regions, as well as among the three primate species. Evolutionary changes in RNA editing were nonetheless evident among the species. Across lifespan, we observed an increase of the RNA editing level with advanced age in both brain regions of all three primate species. Overall design: poly(A) enriched RNAs extracted from pooled samples of two brain regions: CBC and PFC of  chimpanzee and macaque, fragmented, revers transcribed to double-stranded cDNA using random hexamers. Sequencing libraries were prepared according to the paired-end non-strand-specific sample preparation protocol of Illumina. Each sample was sequenced in a separate lane in the Illumina Genome Analyzer II system, using the 75-bp paired-end sequencing protocol. human data was downloaded from SRA [SRP005169]