We created a comprehensive tRNA deletion library in yeast and characterized the phenotypic and further characterized the molecular changes in a subset of deletion strains
A comprehensive tRNA deletion library unravels the genetic architecture of the tRNA pool.
No sample metadata fields
View SamplesSince their discovery, transposable elements have been proposed to play a central role in the evolution of their host genomes through their ability to regulate gene expression, in particular by providing transcription start sites (TSSs) for host genes. To investigate their contribution to developmental gene expression, we developed RAMPAGE, a high-throughput 5'-complete cDNA sequencing approach to accurately discover TSSs, characterize their transcripts, and quantify their expression. This strategy, which directly delineates the expression profiles of individual promoters and was designed to offer optimal sample multiplexing capabilities, represents an advantageous alternative to standard RNA-Seq for a wide range of transcriptome profiling applications. We used RAMPAGE in a genome-wide study of promoter activity throughout 36 stages of the life cycle of Drosophila melanogaster, and describe here a comprehensive dataset that represents the first developmental timecourse of promoter usage. We found that over 40% of developmentally expressed genes have at least 2 promoters, and that alternative promoters generally implement distinct regulatory programs. Transposons harbor TSSs driving the expression of hundreds of annotated genes, and they often impart their own expression specificity upon the genes they regulate. Detailed analysis of particular transposons identified sequence elements encoding these regulatory properties. Our results show that transposable elements contribute significantly to the generation of standing variation and to the evolution of gene regulatory networks, by distributing stereotyped regulatory modules throughout the genome. Overall design: This dataset represents a whole-genome, single-base resolution profiling of transcription start site (TSS) expression throughout 36 stages of the life cycle of Drosophila melanogaster. These profiles were established using RAMPAGE, a high-throughput, high-accuracy 5'-complete cDNA sequencing method implemented on the Illumina platform. Embryos, larvae, pupae and adult flies were collected at specific stages of development, and RAMPAGE profiles were established for pools of whole organisms. The data was analyzed using custom scripts and algorithms that are all available upon request. Supplementary files: Dmel_Combined_+.bw: bigWig coverage by cDNA 5' ends (+ strand). Dmel_Combined_-.bw: bigWig coverage by cDNA 5' ends (- strand). Dmel_All_RAMPAGE_peaks.bed: BED file describing all RAMPAGE peaks. Dmel_GeneTSS_RAMPAGE_peaks.bed: BED file describing all peaks attributed to annotated genes. GeneTSS_expression_RAMPAGE_RPM.txt: Expression matrix for all genic peaks (RPM: reads per million). Transposon_expression_RAMPAGE_RPM.txt: Expression matrix for all RepeatMasker-annotated transposon classes (RPM: reads per million). Genome build: dm3
Conserved noncoding transcription and core promoter regulatory code in early <i>Drosophila</i> development.
Sex, Specimen part, Cell line, Subject
View Samples5''-complete cDNA sequencing on ribosome-depleted total RNA from the human K562 cell line. Provides high-quality, genome-wide single-base resolution profiling of transcription start sites and their expression levels. Overall design: This dataset represents a whole-genome, single-base resolution profiling of transcription start site (TSS) expression in the human K562 cell line. These profiles were established using RAMPAGE, a high-throughput, high-accuracy 5''-complete cDNA sequencing method implemented on the Illumina platform. The data was analyzed using custom scripts and algorithms that are all available upon request.
High-fidelity promoter profiling reveals widespread alternative promoter usage and transposon-driven developmental gene expression.
Cell line, Subject
View SamplesWhile the genome sequence of many animals is now complete, their transcriptomes are less well characterised. Both genome-scale tiling arrays and massively parallel sequencing now allow transcriptomes to be mapped at unprecedented depth. We used both technologies to map the C. elegans transcriptome across development. This unbiased overview can serve as a framework for assessing transcriptome changes in a mutant animal and we compared the wild-type data with that of animals that have lost the nonsense-mediated decay (NMD) pathway. Results We find that while the great majority of detectable transcripts map to known gene structures, over 5% of transcribed regions are novel, falling outside current gene annotations. We show that at least 40% of these are novel exons. We also used both technologies to assess isoform complexity and estimate that at least 17% of genes change their major isoform across development. Having mapped the wild-type transcriptome, we examined how this is perturbed in animals lacking nonsense -mediated decay (NMD). NMD prevents expression of prematurely truncated proteins by degrading transcripts containing premature termination codons (PTCs). We find that ~20% of all genes produce transcripts that appear to be targets for NMD. While most of these arise from splicing errors, NMD targets are also enriched for transcripts that contain short open reading frames upstream of the predicted translational start (uORFs). We find an intriguing relationship between the strength of Kozak consensus surrounding the true start codon and the degree to which these uORF containing transcripts are targeted by NMD, suggesting that translational efficiency may be coupled to transcript turnover via the NMD pathway for many transcripts. Conclusions We have generated a high-resolution map of the C. elegans transcriptome and have used it to identify transcripts that are endogenous targets of the NMD machinery. We find that these targets arise principally through splicing errors and suggest that splicing and NMD are highly interlinked processes.
High resolution transcriptome maps for wild-type and nonsense-mediated decay-defective Caenorhabditis elegans.
No sample metadata fields
View SamplesIn autoimmune diseases, accumulation of activated leukocytes correlates with inflammation and disease progression, and therefore, disruption of leukocyte trafficking is an active area of research. The protein kinase Tpl2 (MAP3K8) regulates leukocyte inflammatory responses and is also being investigated for therapeutic inhibition during autoimmunity. Herein, we addressed the contribution of Tpl2 to the regulation of macrophage chemokine and chemokine receptor expression and subsequent migration in vivo using a mouse model of Tpl2 ablation. We found that gene expression of the chemokine ligands CCL2, CCL7, CXCL2, and CXCL3 as well as the chemokine receptors CCR1 and CCR5 were reduced in macrophages from the bone marrow and peritoneal cavities of tpl2-/- mice following stimulation with LPS. LPS stimulation repressed chemokine receptor expression of CCR1, CCR2 and CCR5. Notably, LPS-induced repression of CCR1 and CCR5 was significantly enhanced in Tpl2-deficient macrophages and was observed to be dependent upon Erk activation and independent of PI3K and mTOR signaling. Consistent with alterations in chemokine and chemokine receptor expression, tpl2-/- macrophages were defective in trafficking to the peritoneal cavity following thioglycollate-induced inflammation. Overall, this study demonstrates a Tpl2-dependent mechanism for macrophage expression of both chemokine receptors and their ligands and provides further insight into how Tpl2 inhibition may disrupt inflammatory networks in vivo.
Tumor progression locus 2 (Tpl2) kinase promotes chemokine receptor expression and macrophage migration during acute inflammation.
Treatment
View SamplesRNA-Seq on libraries made from serial dilutions of mRNA from Drosophila melanogaster S2 cell and the External RNA Controls Consortium (ERCC) external RNA controls. We evaluated performance of RNA-Seq by serially diluting a complex pool of known synthetic PolyA+ mRNAs from the External RNA Controls Consortium (ERCC) and PolyA+ mRNA from Drosophila S2 cells. ERCC mRNAs were obtained under Phase V testing from the National Institutes of Standards and Technology (NIST). The ERCC pool contained 96 species of mRNA of various lengths and GC content covering a 2^20 concentration range. Libraries were constructed with 100ng to 10pg of input mRNA. Our data shows an outstanding linear fit between RNA-Seq read density and known input amounts. Overall design: We performed RNA-Seq from libraries made with 0.01ng to 100ng mRNA (mixture of mRNA from Drosophila melanogaster S2 cells and ERCC RNA controls). One RNA-Seq library was prepared with 100ng mRNA and six libraries were made with serial dilutions of mRNA using a modified protocol (see Sample ''extraction protocol''). One lane was sequenced for each library and all seven libraries were run on the same flow cell.
Synthetic spike-in standards for RNA-seq experiments.
Cell line, Subject
View SamplesWe investigated the transcriptional effects of p63 binding by analyzing ME180 cells depleted for all p63 isoforms via expression of a small hairpin RNA (shRNA) targeting the p63 oligomerization domain.
Relationships between p63 binding, DNA sequence, transcription activity, and biological function in human cells.
Age
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Evidence for compensatory upregulation of expressed X-linked genes in mammals, Caenorhabditis elegans and Drosophila melanogaster.
Sex, Specimen part, Cell line, Treatment
View SamplesExpression levels of human genes vary extensive among individuals. Gene expression determines cell function and characteristics thus this variation likely contributes to phenotypic variation. Genetic studies have shown that there is a heritable component to gene expression variation, and have identified genomic regions that contain polymorphic regulators. However, most of these regions are quite large, and few regulators have been identified. In this genetic of gene expression study, we used a large sample to search the genome for polymorphic regulators that influence gene expression, and followed up the results with deep sequencing of transcriptomes and molecular analyses. Key word(s): Transcriptome Analysis Overall design: genetics of gene expression study, 41 Coriell cell line samples examined.
Evidence for compensatory upregulation of expressed X-linked genes in mammals, Caenorhabditis elegans and Drosophila melanogaster.
No sample metadata fields
View SamplesBoth transcription and post-transcriptional processes, such as alternative splicing, play crucial roles in controlling developmental programs in metazoans. Recently emerged RNA-seq method has brought our understanding of eukaryotic transcriptomes to a new level, because it can resolve both gene expression level and alternative splicing events simultaneously. To gain a better understanding of cellular differentiation in gonads, we analyzed mRNA profiles from Drosophila testes and ovaries using RNA-seq. We identified a set of genes that have sex-specific isoforms in wild-type (WT) gonads, including several transcription factors. We found that differentiation of sperms from undifferentiated germ cells induced a dramatic downregulation of RNA splicing factors. Our data confirmed that RNA splicing events are significantly more frequent in the undifferentiated cell-enriched bag of marbles (bam) mutant testis, but downregulated upon differentiation in WT testis. Consistent with this, we showed that genes required for meiosis and terminal differentiation in WT testis were mainly regulated at the transcriptional level, but not by alternative splicing. Unexpectedly, we observed an increase in expression of all families of chromatin remodeling factors and histone modifying enzymes in the undifferentiated cell-enriched bam testis. More interestingly, chromatin regulators and histone modifying enzymes with opposite enzymatic activities are coenriched in undifferentiated cells in testis, suggesting that these cells may possess dynamic chromatin architecture. Finally, our data revealed many new features of the Drosophila gonadal transcriptomes, and will lead to a more comprehensive understanding of how differential gene expression and splicing regulate gametogenesis in Drosophila. Our data provided a foundation for the systematic study of gene expression and alternative splicing in many interesting areas of germ cell biology in Drosophila, such as the molecular basis for sexual dimorphism and the regulation of the proliferation vs terminal differentiation programs in germline stem cell lineages. Overall design: RNA-Seq experiments for four Drosophila melanogaster samples: (1) bam mutant testes, (2) wild-type testes, (3) bam mutant ovaries, (4) wild-type ovaries
Evidence for compensatory upregulation of expressed X-linked genes in mammals, Caenorhabditis elegans and Drosophila melanogaster.
Specimen part, Subject
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