Evolutionary and ontogenetic changes in RNA editing in human, chimpanzee and macaque brains
Ontology highlight
ABSTRACT:
ORGANISM(S): Pan troglodytes Macaca mulatta
PROVIDER: GSE45244 | GEO | 2014/01/07
SECONDARY ACCESSION(S): PRJNA193311
REPOSITORIES: GEO
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Project description: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. 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]
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Project description:The human brain is about three times larger than the brain of our closest relatives, chimpanzees and bonobos. However, increased size alone fails to explain cognitive abilities unique to humans. Functional changes acquired in the human lineage are likely mediated by divergent gene expression and cell composition in brain regions. Here we generated a map of the human brain transcriptome by assessing the gene expression levels in 33 distinct regions representing all major brain structures from four adult cognitively healthy human individuals, three chimpanzees, three bonobos, and three rhesus macaques. We further conducted single-nuclei RNA-sequencing (SN-seq) experiment in three of the 33 brain regions in four species: two regions showing excess of the human-specific differences, cingulate anterior cortex and cerebellar gray matter, as well as one region showing no such excess, caudate nucleus. We determined cell type specificity of human-specific differences observed in the bulk tissue analysis, and identified species-specific expression differences directly using SN-seq data. This data resource forms a comprehensive baseline for studies of normal and abnormal human brain function and evolution.
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