MRNA-Seq of whole adult females and males, and miixed sex embryos, from multiple Drosophila species
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ABSTRACT: We performed transcriptional profiling of sexed whole adults and mixed sex embryos of eight Drosophila species. These data were used in a comparative transcriptomics analysis of multiple Drosophila species to define functional elements conserved throughout the Drosophila genus. For each species, wild-type inbred strains were analysed. Each sample represents an independent pool of flies (30 flies for adult samples, 200-300 ml for embryos).
Project description:The model organism Encyclopedia of DNA Elements project (modENCODE) has produced a comprehensive annotation of D. melanogaster transcript models based on an enormous amount of high-throughput experimental data. However, some transcribed elements may not be functional, and technical artifacts may lead to erroneous inference of transcription. Inter-species comparison provides confidence to predicted annotation, since transcriptional activity that has been evolutionarily conserved is likely to have an advantageous function. We have performed RNA-Seq and CAGE-Seq experiments on more than 80 samples from multiple tissues and stages of 15 Drosophila species, including 8 previously unsequenced genomes. We have found strikingly conserved sequence, expression, and splicing for the vast majority of transcript models in modENCODE annotation (e.g. 99% exons of coding sequences (CDS), 88% exons of untranslated regions (UTR), and 87% splicing events), indicating that the transcriptome annotation is of very high quality. We also describe dynamic transcriptome evolution within the Drosophila genus, including conserved promoter structure, labile positions of transcription start sites, and rapidly evolving RNA-editing events. We demonstrate how this phylogenetic approach to DNA element validation will prove useful in the annotation of other high priority genomes, especially for genomes that are less compact than Drosophila (e.g. the vast majority of vertebrate genomes). Refer to individual Series (listed below).
Project description:Background: Microorganisms are the major cause of food spoilage during storage, processing and distribution. Pseudomonas fluorescens is a typical spoilage bacterium that contributes to a large extent to the spoilage process of proteinaceous food. RpoS is considered an important global regulator involved in stress survival and virulence in many pathogens. Our previous work revealed that RpoS contributed to the spoilage activities of P. fluorescens by regulating resistance to different stress conditions, extracellular acylated homoserine lactone (AHL) levels, extracellular protease and total volatile basic nitrogen (TVB-N) production. However, RpoS-dependent genes in P. fluorescens remained undefined. Results: RNA-seq transcriptomics analysis combined with quantitative proteomics analysis basing on multiplexed isobaric tandem mass tag (TMT) labeling was performed for the P. fluorescens wild-type strain UK4 and its derivative carrying a rpoS mutation. A total of 375 differentially expressed genes (DEGs) and 212 differentially expressed proteins (DEPs) were identified in these two backgrounds. The DGEs were further verified by qRT-PCR tests, and the genes directly regulated by RpoS were confirmed by 5’-RACE-PCR sequencing. The combining transcriptome and proteome analysis revealed a role of this regulator in several cellular processes, including polysaccharide metabolism, intracellular secretion and extracellular structures, cell well biogenesis, stress responses, ammonia and biogenic amine production, which may contribute to biofilm formation, stress resistance and spoilage activities of P. fluorescens. Moreover, in this work we indeed observed that RpoS contributed to the production of the macrocolony biofilm’s matrix.
Project description:Phase separation of biomolecules into condensates is a key mechanism in the spatiotemporal organization of biochemical processes in cells. We systematically engineered light-inducible transcription factor condensates with different material properties and analyzed their influence on transcription activation. When transcription factor condensates were transformed into solid-like gels, we observed a reduced activation of gene expression. We wanted to evaluate the impact that the condensate formation of the transcription factor RelA had on its endogenous promoters using expression data. To this aim, HEK-293T cells were transfected either with empty vector (1-3) or eGFP-RelA (4-6) or eGFP-RelA, Cry2olig-mCh-FUSN-NLS-NbGFP and Cry2olig-mCh-FUSN-NLS, along with an NF-κB-responsive SEAP reporter (7-9). In each of the three groups of transfected cells, 8 h after transfection, 3 samples were kept in the dark (D) and 3 under blue light illumination (BL, 5 μmol m-² s-1) for 24 h prior to RNA extraction. RNA-seq libraries from the 18 samples were sequenced by BGI on a DNBSEQ platform using paired-end chemistry with a read length of 100 base pairs each. Each strand was sequenced across two separate lanes (L03, L04), generating a total of 4 FASTQ files per sample.
Project description:In a previous study, we found that H2S alleviates salinity stress in cucumber by maintaining the Na+/K+ balance and by regulating H2S metabolism and the oxidative stress response. However, little is known about the molecular mechanisms behind H2S-regulated salt-stress tolerance in cucumber. Here, an integrated transcriptomic and proteomic analysis based on RNA-seq and 2-DE was used to investigate the global mechanism underlying H2S-regulated salt-stress tolerance. In total, 11 761 differentially expressed genes (DEGs) and 61 differentially expressed proteins (DEPs) were identified. Analysis of the pathways associated with the DEGs showed that salt stress enriched expression of genes in primary and energy metabolism, such as photosynthesis, carbon metabolism and biosynthesis of amino acids. Application of H2S significantly decreased these DEGs but enriched DEGs related to plant-pathogen interaction, sulfur-containing metabolism, cell defense and signal transduction pathways. Notably, changes related to sulfur-containing metabolism and cell defense were also observed through proteome analysis, such as Cysteine synthase 1, Glutathione S-transferase U25-like, Protein disulfide-isomerase and Peroxidase 2. We present the first global analysis of the mechanism underlying H2S regulation of salt-stress tolerance in cucumber through tracking changes in the expression of specific proteins and genes.
Project description:High density yeast tiling array reveals new introns and extensive meiotic splicing regulation. Knowing gene structure is vital to understanding gene function, and accurate genome annotation is essential for understanding cellular function. To this end, we have developed an assay for genome-wide mapping of introns in Saccharomyces cerevisiae. Using high-density tiling arrays we compared wild type yeast to a mutant deficient for intron degradation. Our method identified 76% of the known introns, verified the existence of an additional 18 predicted introns, and revealed six new introns. Furthermore, we discovered that all 13 meiosis-specific intronic yeast genes undergo regulated splicing, which provides post-transcriptional regulation of the genes involved in yeast cell differentiation. Moreover, we found that >10% of intronic genes in yeast are incompletely spliced during exponential growth in rich media, suggesting that meiosis is not the only cellular function regulated by splicing. The method provides a clear snapshot of the spliced transcriptome in yeast. Our tiling array assay can be used to explore a variety of cellular environments and should be readily adaptable to the study of other organisms including humans.
Project description:Stomatal guard-cells modulate gas exchange between the plant and the atmosphere.<br><br>Regulation of transcription is emerging as an important mechanism in<br><br>controlling guard cells activity. The Arabidopsis transcription factor<br><br>AtMYB60, is specifically expressed in guard cells and controls stomatal<br><br>movements. Opening of stomatal pores is constitutively reduced in the<br><br>atmyb60-1 null allele, and water loss during drought is diminished in<br><br>the mutant compared to wild type. To address the effect of the AtMYB60<br><br>disruption on global gene expression, total mRNAs, derived from<br><br>atmyb60-1 and WT rosette leaves, grown in standard conditions, were hybridized to a cDNA microarray.
Project description:We introduce an approach to transcript discovery coupled with a statistical model for RNA-Seq experiments that produces estimates of transcript abundances. Our algorithms are implemented in an open source software program called Cufflinks. To test Cufflinks, we sequenced and analyzed more than 430 million paired 75bp RNA-Seq reads from a mouse myoblast cell line representing a differentiation timeseries. We detected 13,689 known transcripts and 3,724 previously unannotated ones, 62% of which are supported by independent expression data or by homologous genes in other species. Analysis of transcript expression over the timeseries revealed complete switches in the dominant transcription start site (TSS) or splice-isoform in 330 genes, along with more subtle shifts in a further 1,304 genes. These dynamics suggest substantial regulatory flexibility and complexity in this well-studied model of muscle development. Timeseries of C2C12 myoblast RNA-Seq
Project description:Background: Recent studies have demonstrated that antisense transcription is pervasive in budding yeasts and is conserved between Saccharomyces cerevisiae and S. paradoxus. While studies have examined antisense transcripts of S. cerevisiae for inverse transcription in stationary phase and stress conditions, there is a lack of comprehensive analysis of the conditional specific evolutionary characteristics of antisense transcription between yeasts. Here we attempt to decipher the evolutionary relationship of antisense transcription of S. cerevisiae and S. paradoxus cultured in mid log, early stationary phase, and heat shock conditions. Results: Massively parallel sequencing of sequence strand-specific cDNA library was performed from RNA isolated from S. cerevisiae and S. paradoxus cells at mid log, stationary phase and heat shock conditions. We performed this analysis using a stringent set of sense ORF transcripts and non-coding antisense transcripts that were expressed in all the three conditions, as well as in both species. We found the divergence of the condition specific anti-sense transcription levels is higher than that in condition specific sense transcription levels, suggesting that antisense transcription played a potential role in adapting to different conditions. Furthermore, 43% of sense-antisense pairs demonstrated inverse transcription in either stationary phase or heat shock conditions relative to the mid log conditions. In addition, a large part of sense-antisense pairs (67%), which demonstrated inverse transcription, were highly conserved between the two species. Our results were also concordant with known functional analyses from previous studies and with the evidence from mechanistic experiments of role of individual genes. Conclusions: This study provides a comprehensive picture of the role of antisense transcription mediating sense transcription in different conditions across yeast species. We can conclude from our findings that antisense regulation could act like an on-off switch on sense regulation in different conditions. Transcriptomes of two yeast species under mid-log phase, early stationary phase, and after heat shock treatment were generated by Illumina HiSeq 2000 paired-end sequencing
Project description:We sequenced dissected ovaries and testes (with reproductive tracts) as well as female and male carcasses in two species of Drosophila in order to validate gene predictions from the ModENCODE project. Comparison of dissected reproductive tracts and remaining carcasses between D. simulans and D. pseudoobscura
Project description:MDA231, BT549, and SUM159PT basal-like breast cancer cell lines were transfected with non-targeting siRNA (siCONTROL), siRNA targeting DUSP4 (siDUSP4), or siCONTROL + 4 or 24 hr of 1uM selumetinib. Cells were harvested at 96 hr post-siRNA transfection. Data were Log2 RMA normalized. We sought to identify changes in gene expression after MEK inhibition, or after loss of DUSP4 function in breast cancer cell lines.