Conserved Function of lincRNAs in Vertebrate Embryonic Development Despite Rapid Sequence Evolution
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ABSTRACT:
ORGANISM(S): Danio rerio
PROVIDER: GSE32880 | GEO | 2011/12/22
SECONDARY ACCESSION(S): PRJNA146609
REPOSITORIES: GEO
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Project description:Thousands of large intervening non-coding RNAs (lincRNAs) have been identified in mammals. To better understand the evolution and functions of these enigmatic RNAs, we used chromatin marks, poly(A)-site mapping and RNA-Seq data, to identify more than 550 distinct lincRNAs in zebrafish. Although these shared many characteristics with mammalian lincRNAs, only 29 had detectable sequence similarity with putative mammalian orthologs, typically restricted to a single short region of high conservation. Other lincRNAs had conserved genomic locations without detectable sequence conservation. Antisense reagents targeting conserved regions of two zebrafish lincRNAs caused developmental defects. Reagents targeting splice sites caused the same defects and were rescued by adding either the mature lincRNA or its human or mouse ortholog. Our study provides a roadmap for identification and analysis of lincRNAs in model organisms and shows that lincRNAs play crucial biological roles during embryonic development with functionality conserved despite limited sequence conservation. H3K4me3, H3K36me3 chromatin maps, 3P-Seq and RNA-Seq were used to identify lincRNAs in the zebrafish genome
2011-12-22 | E-GEOD-32880 | biostudies-arrayexpress
Project description:Super-enhancers (SEs) are key transcriptional drivers of cellular, developmental and disease states in mammals, yet the conservational and regulatory features of these enhancer elements in non-mammalian vertebrates are unknown. To define SEs in zebrafish and enable sequence and functional comparisons to mouse and human SEs, we used genome-wide histone H3 lysine 27 acetylation (H3K27ac) occupancy as a primary SE delineator. Our study determined the set of SEs in pluripotent state cells and adult zebrafish tissues and revealed both similarities and differences between zebrafish and mammalian SEs. Although the total number of SEs was proportional to the genome size, the genomic distribution of zebrafish SEs differed from that of the mammalian SEs. Despite the evolutionary distance separating zebrafish and mammals and the low overall SE sequence conservation, ~42% of zebrafish SEs from all cells and tissues analyzed were associated with orthologs that also were associated with SEs in mouse and human. Compared to their non-associated counterparts, higher sequence conservation was revealed for those SEs that have maintained orthologous vertebrate gene associations. Functional dissection of two of these SEs identified conserved sequence elements and tissue-specific expression patterns, while chromatin accessibility analyses predicted transcription factors governing the function of pluripotent state zebrafish SEs. Our zebrafish enhancer characterizations and comparative studies show the extent of SE usage and their conservation across vertebrates, permitting future gene regulatory studies in several tissues.
2016-11-14 | GSE75734 | GEO
Project description:Numerous studies over the past decade have elucidated a substantial set of long intergenic noncoding RNAs (lincRNAs). It has since become clear that lincRNAs constitute an important layer of genome regulation across a wide spectrum of species. Yet, the factors governing their evolution and origins remain relatively unexplored. One possible factor that may have shaped lincRNA biology are transposable elements (TEs). Here we set out to comprehensively characterize the TE content of lincRNAs relative to genomic averages and protein coding transcripts. Our analysis of the TE composition across 9241 human lincRNAs revealed that, in sharp contrast to protein coding genes, a striking majority (83%) of lincRNAs contain a TE, and TEs comprise 42% of lincRNA transcript sequences. LincRNA TE composition varies significantly from genomic averages, being depleted of LI and Alu elements and enriched for a broad class of endogenous retroviruses (ERVs). Furthermore, specific TE families occur in biased positions and orientations within lincRNAs, particularly at their transcription start sites, suggesting a role in the origin of those lincRNAs. Finally, we find that TEs can drive gene expression regulation of lincRNAs—we observed a dramatic correlation between lincRNAs containing HERVH elements and almost exclusive expression in pluripotent cells. Conversely, those lincRNAs that are devoid of TEs are more highly expressed in testis. Collectively, TEs pervade lincRNAs and have shaped lincRNA evolution and function via bestowing tissue-specific expression from donated transcriptional regulatory signals. We extracted profiled the transcriptome expression polyadenylated mRNA-Seq. We then used these to reconstruct the transcriptome using de-novo assemblers and identify long non coding RNAs and their expression.
2013-01-22 | E-GEOD-38993 | biostudies-arrayexpress
Project description:Numerous studies over the past decade have elucidated a substantial set of long intergenic noncoding RNAs (lincRNAs). It has since become clear that lincRNAs constitute an important layer of genome regulation across a wide spectrum of species. Yet, the factors governing their evolution and origins remain relatively unexplored. One possible factor that may have shaped lincRNA biology are transposable elements (TEs). Here we set out to comprehensively characterize the TE content of lincRNAs relative to genomic averages and protein coding transcripts. Our analysis of the TE composition across 9241 human lincRNAs revealed that, in sharp contrast to protein coding genes, a striking majority (83%) of lincRNAs contain a TE, and TEs comprise 42% of lincRNA transcript sequences. LincRNA TE composition varies significantly from genomic averages, being depleted of LI and Alu elements and enriched for a broad class of endogenous retroviruses (ERVs). Furthermore, specific TE families occur in biased positions and orientations within lincRNAs, particularly at their transcription start sites, suggesting a role in the origin of those lincRNAs. Finally, we find that TEs can drive gene expression regulation of lincRNAs—we observed a dramatic correlation between lincRNAs containing HERVH elements and almost exclusive expression in pluripotent cells. Conversely, those lincRNAs that are devoid of TEs are more highly expressed in testis. Collectively, TEs pervade lincRNAs and have shaped lincRNA evolution and function via bestowing tissue-specific expression from donated transcriptional regulatory signals.
2013-01-22 | GSE38993 | GEO
Project description:There is growing recognition that mammalian cells produce many thousands of large intergenic transcripts. However, the functional significance of these transcripts has been particularly controversial. While there are some well-characterized examples, the vast majority (>95%) show little evidence of evolutionary conservation and have been suggested to represent transcriptional noise. Here, we report a new approach to identifying large non-coding RNAs (ncRNAs) by using chromatin-state maps to discover discrete transcriptional units intervening known protein-coding loci. Our approach identified ~1600 large multi-exonic RNAs across four mouse cell types. In sharp contrast to previous collections, these large intervening ncRNAs (lincRNAs) exhibit strong purifying selection in their genomic loci, exonic sequences, and promoter regions – with greater than 95% showing clear evolutionary conservation. We also developed a novel functional genomics approach that assigns putative functions to each lincRNA, revealing a diverse range of roles for lincRNAs in processes from ES pluripotency to cell proliferation. We obtained independent functional validation for the predictions for over 100 lincRNAs, using cell-based assays. In particular, we demonstrate that specific lincRNAs are transcriptionally regulated by key transcription factors in these processes such as p53, NFKB, Sox2, Oc4, and Nanog. Together, these results define a unique collection of functional lincRNAs that are highly conserved and implicated in diverse biological processes. lincRNA expression patterns were generated across a compendium of mouse tissues, cell types, and conditions. lincRNA expression profiles were generated on custom NimbleGen arrays (Samples GSM346609..GSM346650) and correlated with known protein coding genes on Affymetrix gene expression arrays (Samples GSM347910..GSM347943).
2009-01-01 | E-GEOD-13765 | biostudies-arrayexpress
Project description:There is growing recognition that mammalian cells produce many thousands of large intergenic transcripts. However, the functional significance of these transcripts has been particularly controversial. While there are some well-characterized examples, the vast majority (>95%) show little evidence of evolutionary conservation and have been suggested to represent transcriptional noise. Here, we report a new approach to identifying large non-coding RNAs (ncRNAs) by using chromatin-state maps to discover discrete transcriptional units intervening known protein-coding loci. Our approach identified ~1600 large multi-exonic RNAs across four mouse cell types. In sharp contrast to previous collections, these large intervening ncRNAs (lincRNAs) exhibit strong purifying selection in their genomic loci, exonic sequences, and promoter regions – with greater than 95% showing clear evolutionary conservation. We also developed a novel functional genomics approach that assigns putative functions to each lincRNA, revealing a diverse range of roles for lincRNAs in processes from ES pluripotency to cell proliferation. We obtained independent functional validation for the predictions for over 100 lincRNAs, using cell-based assays. In particular, we demonstrate that specific lincRNAs are transcriptionally regulated by key transcription factors in these processes such as p53, NFKB, Sox2, Oc4, and Nanog. Together, these results define a unique collection of functional lincRNAs that are highly conserved and implicated in diverse biological processes.
2009-01-01 | GSE13765 | GEO
Project description:While thousands of large intergenic non-coding RNAs (lincRNAs) have been identified in mammals, few have been functionally characterized leading to debate about their biological role. To address this, we performed loss-of-function studies on most lincRNAs expressed in mouse embryonic stem cells (ESC) and characterized the effects on gene expression. Here we show that knockdown of lincRNAs have major consequences on gene expression patterns, comparable to knockdown of well-known ESC regulators. Notably, lincRNAs primarily affect gene expression in trans. We identify dozens of lincRNAs whose knockdown causes an exit from the pluripotent state or upregulation of lineage commitment programs. We integrate lincRNAs into the molecular circuitry of ESCs and show that lincRNA genes are regulated by key transcription factors and that lincRNA transcripts physically bind to multiple chromatin regulatory proteins to affect shared gene expression programs. Together, the results demonstrate that lincRNAs have key roles in the circuitry controlling ESC state. We generated five lentiviral-based shRNAs targeting each of the 237 lincRNAs previously identified in ESCs. These shRNAs successfully targeted 147 lincRNAs and reduced their expression by an average of ~75% compared to endogenous levels in ESCs. As positive controls, we generated shRNAs targeting ~50 genes encoding regulatory proteins, including both transcription factor and chromatin factor genes that have been shown to play critical roles in ESC regulation; we obtained validated hairpins against 40 of these genes. As negative controls, we performed independent infections with lentiviruses containing 27 different shRNAs with no known cellular target RNA.
2011-08-29 | E-GEOD-30245 | biostudies-arrayexpress
Project description:While thousands of large intergenic non-coding RNAs (lincRNAs) have been identified in mammals, few have been functionally characterized leading to debate about their biological role. To address this, we performed loss-of-function studies on most lincRNAs expressed in mouse embryonic stem cells (ESC) and characterized the effects on gene expression. Here we show that knockdown of lincRNAs have major consequences on gene expression patterns, comparable to knockdown of well-known ESC regulators. Notably, lincRNAs primarily affect gene expression in trans. We identify dozens of lincRNAs whose knockdown causes an exit from the pluripotent state or upregulation of lineage commitment programs. We integrate lincRNAs into the molecular circuitry of ESCs and show that lincRNA genes are regulated by key transcription factors and that lincRNA transcripts physically bind to multiple chromatin regulatory proteins to affect shared gene expression programs. Together, the results demonstrate that lincRNAs have key roles in the circuitry controlling ESC state.
2011-08-30 | GSE30245 | GEO
Project description:Background: LincRNAs play critical roles in eukaryotic cells, but systematic analyses of lincRNAs of an animal for phenotypes have been missing. We have generated CRISPR knockout strains for C. elegans lincRNAs and have evaluated their phenotypes Results: C. elegans lincRNAs demonstrate global features such as shorter length and fewer exons than mRNAs. For the systematic evaluation of C. elegans lincRNAs, CRISPR knockout strains for 155 out of all the 170 C. elegans lincRNAs were produced. Mutants of 23 lincRNAs have shown phenotypes in 6 traits analyzed. We have investigated these phenotypic lincRNAs for their gene expression patterns and their potential functional mechanisms. Some C. elegans lincRNAs play cis roles to modulate the expression of their neighboring genes, and some other lincRNAs play trans roles as ceRNAs against microRNAs. LincRNAs are extensively regulated by transcription factors, and we dissect the pathway that two transcription factors UNC-30 and UNC-55 control the expression of linc-73 together. Furthermore, linc-73 plays a cis role to modulate the expression of its neighboring gene unc-104, and thus regulates the formation of presynapses. Conclusions: By using CRISPR/cas9 technology, we have generated knockout strains of 155 C. elegans lincRNAs as valuable resources for studies in noncoding RNAs, and we provide biological insights for 23 phenotypic lincRNAs identified from 6 traits examined.
2018-12-27 | GSE122973 | GEO
Project description:Background: LincRNAs play critical roles in eukaryotic cells, but systematic analyses of lincRNAs of an animal for phenotypes have been missing. We have generated CRISPR knockout strains for C. elegans lincRNAs and have evaluated their phenotypes Results: C. elegans lincRNAs demonstrate global features such as shorter length and fewer exons than mRNAs. For the systematic evaluation of C. elegans lincRNAs, CRISPR knockout strains for 155 out of all the 170 C. elegans lincRNAs were produced. Mutants of 23 lincRNAs have shown phenotypes in 6 traits analyzed. We have investigated these phenotypic lincRNAs for their gene expression patterns and their potential functional mechanisms. Some C. elegans lincRNAs play cis roles to modulate the expression of their neighboring genes, and some other lincRNAs play trans roles as ceRNAs against microRNAs. LincRNAs are extensively regulated by transcription factors, and we dissect the pathway that two transcription factors UNC-30 and UNC-55 control the expression of linc-73 together. Furthermore, linc-73 plays a cis role to modulate the expression of its neighboring gene unc-104, and thus regulates the formation of presynapses. Conclusions: By using CRISPR/cas9 technology, we have generated knockout strains of 155 C. elegans lincRNAs as valuable resources for studies in noncoding RNAs, and we provide biological insights for 23 phenotypic lincRNAs identified from 6 traits examined.
2018-12-27 | GSE115320 | GEO