Changes in snoRNA and snRNA Abundance in the Human, Chimpanzee, Macaque, and Mouse Brain.
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ABSTRACT:
SUBMITTER: Zhang B
PROVIDER: S-EPMC4824147 | biostudies-literature | 2016 Mar
REPOSITORIES: biostudies-literature
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Project description:Adenosine-to-inosine (A-to-I) substitutions are the most common type of RNA editing in mammals. A-to-I RNA editing is particularly widespread in the brain and is known to play important roles in neuronal functions. In this study we investigated RNA-editing changes during human brain development and maturation, as well as evolutionary conservation of RNA-editing patterns across primates. We used high-throughput transcriptome sequencing (RNA-seq) to quantify the RNA-editing levels and assess ontogenetic dynamics of RNA editing at more than 8000 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, with 40% of the annotated editing sites studied showing divergent editing levels among the three species and 16.5% of sites displaying statistically significant human-specific editing patterns. Across lifespan, we observed an increase of the RNA-editing level with advanced age in both brain regions of all three primate species.
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Project description:Among other factors, changes in gene expression on the human evolutionary lineage have been suggested to play an important role in the establishment of human-specific phenotypes. However, the molecular mechanisms underlying these expression changes are largely unknown. Here, we have explored the role of microRNA (miRNA) in the regulation of gene expression divergence between adult humans, chimpanzees and rhesus macaques, in two brain regions: prefrontal cortex and cerebellum. Using combination of high-throughput sequencing, miRNA microarrays and Q-PCR, we have shown that up to 11% of the 325 expressed miRNA diverged significantly between humans and chimpanzees and up to 31% - between humans and macaques. Measuring mRNA and protein expression in human and chimpanzee brains, we found a significant inverse relationship between the miRNA and the target genes expression divergence, explaining 2-4% of mRNA and 4-6% of protein expression differences. Notably, miRNA showing human-specific expression localize in neurons and target genes that are involved in neural functions. Enrichment in neural functions, as well as miRNA-driven regulation on the human evolutionary lineage, were further confirmed by experimental validation of predicted miRNA targets in two neuroblastoma cell lines. Finally, we identified a signature of positive selection in the upstream region of one of the five miRNA with human-specific expression, miR-34c-5p. This suggests that miR-34c-5p expression change took place after the split of the human and the Neanderthal lineages and had adaptive significance. Taken together these results indicate that changes in miRNA expression might have contributed to evolution of human cognitive functions.
2011-10-18 | GSE26545 | GEO
Project description:BackgroundSmall nucleolar RNAs (snoRNAs) are mid-size non-coding RNAs required for ribosomal RNA modification, implying a ubiquitous tissue distribution linked to ribosome synthesis. However, increasing numbers of studies identify extra-ribosomal roles of snoRNAs in modulating gene expression, suggesting more complex snoRNA abundance patterns. Therefore, there is a great need for mapping the snoRNome in different human tissues as the blueprint for snoRNA functions.ResultsWe used a low structure bias RNA-Seq approach to accurately quantify snoRNAs and compare them to the entire transcriptome in seven healthy human tissues (breast, ovary, prostate, testis, skeletal muscle, liver, and brain). We identify 475 expressed snoRNAs categorized in two abundance classes that differ significantly in their function, conservation level, and correlation with their host gene: 390 snoRNAs are uniformly expressed and 85 are enriched in the brain or reproductive tissues. Most tissue-enriched snoRNAs are embedded in lncRNAs and display strong correlation of abundance with them, whereas uniformly expressed snoRNAs are mostly embedded in protein-coding host genes and are mainly non- or anticorrelated with them. Fifty-nine percent of the non-correlated or anticorrelated protein-coding host gene/snoRNA pairs feature dual-initiation promoters, compared to only 16% of the correlated non-coding host gene/snoRNA pairs.ConclusionsOur results demonstrate that snoRNAs are not a single homogeneous group of housekeeping genes but include highly regulated tissue-enriched RNAs. Indeed, our work indicates that the architecture of snoRNA host genes varies to uncouple the host and snoRNA expressions in order to meet the different snoRNA abundance levels and functional needs of human tissues.
| S-EPMC8176728 | biostudies-literature
Project description:Among other factors, changes in gene expression on the human evolutionary lineage have been suggested to play an important role in the establishment of human-specific phenotypes. However, the molecular mechanisms underlying these expression changes are largely unknown. Here, we have explored the role of microRNA (miRNA) in the regulation of gene expression divergence between adult humans, chimpanzees and rhesus macaques, in two brain regions: prefrontal cortex and cerebellum. Using combination of high-throughput sequencing, miRNA microarrays and Q-PCR, we have shown that up to 11% of the 325 expressed miRNA diverged significantly between humans and chimpanzees and up to 31% - between humans and macaques. Measuring mRNA and protein expression in human and chimpanzee brains, we found a significant inverse relationship between the miRNA and the target genes expression divergence, explaining 2-4% of mRNA and 4-6% of protein expression differences. Notably, miRNA showing human-specific expression localize in neurons and target genes that are involved in neural functions. Enrichment in neural functions, as well as miRNA-driven regulation on the human evolutionary lineage, were further confirmed by experimental validation of predicted miRNA targets in two neuroblastoma cell lines. Finally, we identified a signature of positive selection in the upstream region of one of the five miRNA with human-specific expression, miR-34c-5p. This suggests that miR-34c-5p expression change took place after the split of the human and the Neanderthal lineages and had adaptive significance. Taken together these results indicate that changes in miRNA expression might have contributed to evolution of human cognitive functions. Human, chimpanzee, and rhesus: mRNA, microRNA, and microRNA sequencing. Neuroblastoma cell lines: miRNA transfection experiments were conducted on two human-derived neuroblastoma cell lines (SH-SY5Y and SK-N-SH). Briefly, cells were plated in 0.5ml of growth medium, without antibiotics, 24h prior to transfection. miRNA mimics-Lipofectamine 2000 (Invitrogen) complexes were prepared freshly before transfection according to the manufacturer's protocol. SH-SY5Y and SK-N-SH cells were transfected in six-well plates using miRNA mimics-Lipofectamine 2000 with a final oligonucleotide concentration of 10nmol/L. In parallel, negative control transfections with mock oligonucleotides were conducted according to the manufacturer's protocol. For each cell line, transfections with negative control oligonucleotides were carried out in two independent replicates. Cells were harvested after 24h, total RNA were extracted with Trizol reagent (Invitrogen) and further processed and hybridized to Affymetrix Human Genome U133 Plus 2.0 arrays following the manufacturer's instructions. The gene expression levels were determined using rma in the R Affy package.
2011-10-17 | E-GEOD-26545 | biostudies-arrayexpress
Project description:Among other factors, changes in gene expression on the human evolutionary lineage have been suggested to play an important role in the establishment of human-specific phenotypes. However, the molecular mechanisms underlying these expression changes are largely unknown. Here, we have explored the role of microRNA (miRNA) in the regulation of gene expression divergence among adult humans, chimpanzees, and rhesus macaques, in two brain regions: prefrontal cortex and cerebellum. Using a combination of high-throughput sequencing, miRNA microarrays, and Q-PCR, we have shown that up to 11% of the 325 expressed miRNA diverged significantly between humans and chimpanzees and up to 31% between humans and macaques. Measuring mRNA and protein expression in human and chimpanzee brains, we found a significant inverse relationship between the miRNA and the target genes expression divergence, explaining 2%-4% of mRNA and 4%-6% of protein expression differences. Notably, miRNA showing human-specific expression localize in neurons and target genes that are involved in neural functions. Enrichment in neural functions, as well as miRNA-driven regulation on the human evolutionary lineage, was further confirmed by experimental validation of predicted miRNA targets in two neuroblastoma cell lines. Finally, we identified a signature of positive selection in the upstream region of one of the five miRNA with human-specific expression, miR-34c-5p. This suggests that miR-34c-5p expression change took place after the split of the human and the Neanderthal lineages and had adaptive significance. Taken together these results indicate that changes in miRNA expression might have contributed to evolution of human cognitive functions.
| S-EPMC3192836 | biostudies-literature
Project description:Small nucleolar RNAs (snoRNAs) are an abundant type of non-coding RNA with conserved functions in all known eukaryotes. Classified into two main families, the box C/D and H/ACA snoRNAs, they enact their most well characterized role of guiding site specific modifications in ribosomal RNA, through the formation of specific ribonucleoprotein complexes, with fundamental implications in ribosome biogenesis. However, it is becoming increasingly clear that the landscape of snoRNA cellular functionality is much broader than it once seemed with novel members, non-uniform expression patterns, new and diverse targets as well as several emerging non-canonical functions ranging from the modulation of alternative splicing to the regulation of chromatin architecture. In order to facilitate the further characterization of human snoRNAs in a holistic manner, we introduce an online interactive database tool: snoDB. Its purpose is to consolidate information on human snoRNAs from different sources such as sequence databases, target information, both canonical and non-canonical from the literature and from high-throughput RNA-RNA interaction datasets, as well as high-throughput sequencing data that can be visualized interactively.
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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.
2014-01-07 | GSE45244 | GEO
Project description:In the present study, we applied our 'precise annotation' to the mitochondrial (mt) genomes of human, chimpanzee, rhesus macaque and mouse using 5' and 3' end small RNAs. Our new annotations updated previous annotations. In particular, our new annotations led to two important novel findings: (1) the identification of five Conserved Sequence Blocks (CSB1, CSB2, CSB3, LSP and HSP) in the control regions; and (2) the annotation of Transcription Initiation and novel Transcription Termination Sites. Based on these annotations, we proposed a novel model of mt transcription which can account for the mt transcription and its regulation in mammals. According to our model, Transcription Termination Sites function as switches to regulate the production of short, long primary transcripts and uninterrupted transcription, rather than simply terminate the mt transcription. Moreover, the expression levels of mitochondrial transcription termination factors control the proportions of rRNAs, mRNAs and lncRNAs in total mt RNA. Our findings point to the existence of many other, as yet unidentified, Transcription Termination Sites in mammals.
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Project description:Identification of gene expression traits unique to the human brain sheds light on the molecular mechanisms underlying human evolution. Here, we searched for uniquely human gene expression traits by analyzing 422 brain samples from humans, chimpanzees, bonobos, and macaques representing 33 anatomical regions, as well as 88,047 cell nuclei composing three of these regions. Among 33 regions, cerebral cortex areas, hypothalamus, and cerebellar gray and white matter evolved rapidly in humans. At the cellular level, astrocytes and oligodendrocyte progenitors displayed more differences in the human evolutionary lineage than the neurons. Comparison of the bulk tissue and single-nuclei sequencing revealed that conventional RNA sequencing did not detect up to two-thirds of cell-type-specific evolutionary differences.
| S-EPMC7263190 | biostudies-literature
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]
2014-01-07 | E-GEOD-45244 | biostudies-arrayexpress