Human oncogenes involved in the development of hematological malignancies have been widely used to model experimental leukemia. Here, we used the fli1 promoter in zebrafish to target the expression of oncogenic HRAS to endothelial cells, including the hemogenic endothelium and observed the development of a myelo-erythroid proliferative disease. In larvae, the pathological phenotype is characterized by some disruption of the vascular system with prominent expansion of the caudal hematopoietic tissue, increase of expression of stem cell markers and myelo-erythroid specific genes and production of a large number of l-plastin leukocytes. In mosaic juveniles, increased number of hematopoietic blasts and arrest of myeloid maturation was found in kidney marrow. Peripheral blood showed delays of erythrocyte maturation and increased number of circulating myeloid progenitors. We found that the abnormal phenotype is associated with a down regulation of the Notch pathway as shown by the decrease of expression of Notch target genes, whereas overexpressing an activated form of Notch together with the oncogene prevents the expansion of the myelo-erythroid compartment. This study identifies the downregulation of the Notch pathway following an oncogenic event in the hemogenic endothelium as an important step in the pathogenesis of myelo-erythroid diseases and describes a number of potential effectors of this transformation. Overall design: Methods: mRNA profiles of transgenic zebrafish overexpressing the oncogene HRAS in endothelial cells (Tg(fli1ep:GAL4FF)ubs3; Tg(UAS:eGFP-HRASV12)io006); or expressing activate Notch in endothelial cells (Tg(fli1ep:GAL4FF)ubs3; tg(UAS:NICD)kca3) were generated by deep sequencing using Illumina HiSeq 2000. The sequence reads that passed quality filters were analyzed using the CLC bio Assembly Cell software (version 3.2) and the Ensembl (release 63) predicted cDNAs for the Zv9 genome assembly. qRT–PCR validation was performed using TaqMan and SYBR Green assays.
Targeting oncogene expression to endothelial cells induces proliferation of the myelo-erythroid lineage by repressing the Notch pathway.
No sample metadata fields
View SamplesHomeobox genes of the Hox class are required for proper patterning of skeletal elements and play a role in cartilage differentiation. In transgenic mice with overexpression of Hoxd4 during cartilage development, we observed severe defects, namely physical instability of cartilage, accumulation of immature chondrocytes, and decreased maturation to hypertrophy. To define the molecular basis underlying these defects, we performed gene expression profiling using the Affymetrix microarray platform.
Microarray Analysis of Defective Cartilage in Hoxc8- and Hoxd4-Transgenic Mice.
Specimen part
View SamplesHomeobox genes of the Hox class are required for proper patterning of skeletal elements and play a role in cartilage differentiation. In transgenic mice with overexpression of Hoxc8 during cartilage development, we observed severe defects, namely physical instability of cartilage, accumulation of immature chondrocytes, and decreased maturation to hypertrophy. To define the molecular basis underlying these defects, we performed gene expression profiling using the Affymetrix microarray platform.
Microarray Analysis of Defective Cartilage in Hoxc8- and Hoxd4-Transgenic Mice.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
An MLL/COMPASS subunit functions in the C. elegans dosage compensation complex to target X chromosomes for transcriptional regulation of gene expression.
Sex, Disease
View SamplesHere we exploit the essential process of Xchromosome dosage compensation to elucidate basic mechanisms that control the assembly, genomewide binding, and function of gene regulatory complexes that act over large chromosomal territories. We demonstrate that a subunit of C. elegans MLL/COMPASS, a gene-activation complex, acts within the dosage compensation complex (DCC), a condensin complex, to target the DCC to both X chromosomes of hermaphrodites and thereby reduce chromosome-wide gene expression. The DCC binds to two categories of sites on X: rex sites that recruit the DCC in an autonomous, sequence- dependent manner, and dox sites that reside primarily in promoters of expressed genes and bind the DCC robustly only when attached to X. We find that DCC mutants that abolish rex-site binding do not eliminate dox-site binding, but instead reduce it to the level observed at autosomal binding sites in wild-type animals. Changes in DCC binding to these non-rex sites occur throughout development and correlate with transcriptional activity of adjacent genes. Moreover, autosomal DCC binding is enhanced by rex-site binding in cis in X-autosome fusion chromosomes. Thus, dox and autosomal sites exhibit similar binding properties. Our data support a model for DCC binding in which low-level DCC binding at dox and autosomal sites is dictated by intrinsic properties correlated with high transcriptional activity. Sex-specific DCC recruitment to rex sites then greatly elevates DCC binding to dox sites in cis, which lack intrinsically high DCC affinity on their own. We also show here that the C. elegans DCC achieves dosage compensation through its effects on transcription.
An MLL/COMPASS subunit functions in the C. elegans dosage compensation complex to target X chromosomes for transcriptional regulation of gene expression.
No sample metadata fields
View SamplesBarley cv. Morex inoculated with Fusarium graminearum (isolate Butte 86) or water (mock). Sampled at 24, 48, 72, 96 and 144 hours after treatment. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Jayanand Boddu. The equivalent experiment is BB9 at PLEXdb.]
Transcriptome analysis of the barley-Fusarium graminearum interaction.
Specimen part, Time
View SamplesAnalysis of the role of PARP1 in gene transcription in MCF7 cells under non-stress conditions. The hypothesis was that PARP1 activity in MCF7 cells plays a role in gene transcription. The results indicate that PARP1 inhibition does not significantly affect transcription after 6 hours of treatment.
Basal activity of a PARP1-NuA4 complex varies dramatically across cancer cell lines.
Specimen part, Cell line
View SamplesAnalysis of the role of PARP1 in gene transcription in cell lines with variable PARP1 activity.
Basal activity of a PARP1-NuA4 complex varies dramatically across cancer cell lines.
Specimen part, Cell line
View SamplesHeritable differences in gene expression between individuals are an important source of phenotypic variation. The question of how closely the effects of genetic variation on protein levels mirror those on mRNA levels remains open. Here, we addressed this question by using ribosomal footprinting to examine how genetic differences between two strains of the yeast S. cerevisiae affect translation. Strain differences in translation were observed for hundreds of genes, more than half as many as showed genetic differences in mRNA levels. Similarly, allele specific measurements in the diploid hybrid between the two strains found roughly half as many cis-acting effects on translation as were observed for mRNA levels. In both the parents and the hybrid, strong effects on translation were rare, such that the direction of an mRNA difference was typically reflected in a concordant footprint difference. The relative importance of cis and trans acting variation on footprint levels was similar to that for mRNA levels. Across all expressed genes, there was a tendency for translation to more often reinforce than buffer mRNA differences, resulting in footprint differences with greater magnitudes than the mRNA differences. Finally, we catalogued instances of premature translation termination in the two yeast strains. Overall, genetic variation clearly influences translation, but primarily does so by subtly modulating differences in mRNA levels. Translation does not appear to create strong discrepancies between genetic influences on mRNA and protein levels. Overall design: Ribsosomal footprinting and RNASeq in the two yeast strains BY and RM as well as their diploid hybrid. We generated one library each for the BY and RM parents, and two libraries (biological replicates) for the hybrid data.
Genetic influences on translation in yeast.
Cell line, Subject
View SamplesThe transcriptomic profiling of psoriasis has led to an increased understanding of disease pathogenesis. Although microarray technologies have been instrumental in this regard, it is clear that these tools detect an incomplete set of DEGs. RNA-seq can be used to supplement these prior technologies. Here, the use of RNAseq methods substantially increased the number of psoriasis-related DEGs. Furthermore, DEGs that were uniquely identified by RNA-seq, but not in other published microarray studies, further supported the role of IL-17 and tumor necrosis factor-a synergy in psoriasis. Examination of one of these factors at the protein level confirmed that RNA-seq is a powerful tool that can be used to identify molecular factors present in psoriasis lesions, and may be useful in the identification of therapeutic targets that to our knowledge have not been reported previously. Further studies are in progress to determine the biological significance of DEGs uniquely discovered by RNA-seq. Overall design: To define the transcriptomic profile of psoriatic skin, three pairs of lesional and nonlesional skin biopsy specimens were taken from patients with untreated moderate-to-severe plaque psoriasis.
Transcriptional profiling of psoriasis using RNA-seq reveals previously unidentified differentially expressed genes.
Specimen part, Subject
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