During embryogenesis, enhancer-promoter interactions control gene transcriptional activation. These interactions can be tissue-specific or tissue-invariant and occur mostly within larger insulated regulatory domains called Topologically Associating Domains (TADs). Boundary elements, which delineate the extent of TADs, frequently interact with each other and have been associated with constitutive transcription and CTCF/Cohesin binding. In this work, we set out to investigate the regulatory role of a tissue-invariant, preformed interaction between two boundaries that involve the Shh gene and its unique limb enhancer, the ZRS, located one megabase away. Using CRISPR/Cas9 we specifically perturb CTCF binding sites or constitutive transcription at the ZRS-containing boundary, without altering the enhancer sequence. Using capture-HiC (cHiC) we show that both types of perturbation result in altered preformed chromatin interactions and lead to a reduction of Shh expression in developing limb buds. Finally, we demonstrate that the disruption of the chromatin structure in combination with a hypomorphic ZRS allele results in a dramatic Shh loss- of- function and digit agenesis. We thus propose that preformed chromatin structures can ensure stable enhancer promoter communication during development and robustness of gene transcriptional activation. Overall design: We performed transcriptome analysis to confirm the complete loss of the Lmbr1 transcript due to the deletion of its promoter and to detect other potential non-coding transcripts at the locus.
Preformed chromatin topology assists transcriptional robustness of <i>Shh</i> during limb development.
Cell line, Subject
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A systems biology approach identifies a regulatory network in parotid acinar cell terminal differentiation.
Specimen part
View SamplesTerminal differentiation in parotid acini relies on sustained changes in gene expression during the first few postnatal weeks. Little is known about what drives these changes. Expression measurements along with knowledgebased network analysis was used to develop a prospective gene regulatory network that drives differentiation.
A systems biology approach identifies a regulatory network in parotid acinar cell terminal differentiation.
No sample metadata fields
View SamplesMammalian genomes are organized into megabase-scale topologically associated domains (TADs) that have been proposed to represent large regulatory units. Here we demonstrate that disruption of TADs can cause rewiring of long-range regulatory architecture and result in pathogenic phenotypes. We show that distinct human limb malformations are caused by deletions, inversions, or duplications altering the structure of the TAD-spanning WNT6/IHH/EPHA4/PAX3 locus. Using CRISPR/Cas genome editing, we generated mice with corresponding rearrangements. Both in mouse limb tissue and patient-derived fibroblasts, disease-relevant structural changes cause ectopic interactions between promoters and non-coding DNA, and a cluster of limb enhancers normally associated with Epha4 is misplaced relative to TAD boundaries and drives ectopic limb expression of another gene in the locus. Our results demonstrate the functional importance of TADs for orchestrating gene expression via genome architecture and indicate criteria for predicting the pathogenicity of human structural variants, particularly in non-coding regions of the human genome. Overall design: RNA-seq profile of developing distal limbs of mutants and WT animals at E11.5
Disruptions of topological chromatin domains cause pathogenic rewiring of gene-enhancer interactions.
No sample metadata fields
View SamplesGenome-scale methods have identified subchromosomal structures so-called topologically associated domains (TADs) that subdivide the genome into discrete regulatory units, establish with their target genes. By re-engineering human duplications at the SOX9 locus in mice combined with 4C-seq and Capture Hi-C experiments, we show that genomic duplications can result in the formation of novel chromatin domains (neo-TADs) and that this process determines their molecular pathology. Overall design: RNA-seq of embryonic limb buds for WT and mutant animals carrying structural variations at the Sox9/Kcnj locus.
Formation of new chromatin domains determines pathogenicity of genomic duplications.
Specimen part, Subject
View SamplesWe prepared small RNA libraries from 29 tumor/normal pairs of human cervical tissue samples. Analysis of the resulting sequences (42 million in total) defined 64 new human microRNA (miRNA) genes. Both arms of the hairpin precursor were observed in twenty-three of the newly identified miRNA candidates. We tested several computational approaches for analysis of class differences between high throughput sequencing datasets, and describe a novel application of log linear model that has provided the most datasets, and describe a novel application of log linear model that has provided the most effective analysis for this data. This method resulted in the identification of 67 miRNAs that were differentially-expressed between the tumor and normal samples at a false discovery rate less than 0.001. Overall design: A total of 29 tumor/normal pairs of human cervical tissue samples were analyzed. Two samples (G699N_2 and G761T_2) were performed in duplicates. No Fastq files for GSM532871 to GSM532889, GSM532929, and GSM532930. Sequence files are provided as text files for these 22 Sample records in GSE20592_RAW.tar. 38 samples with quality scores are available from SRA as SRP002/SRP002326 (see Supplementary file below).
Ultra-high throughput sequencing-based small RNA discovery and discrete statistical biomarker analysis in a collection of cervical tumours and matched controls.
No sample metadata fields
View SamplesThe selective impact of pathogen epidemics on host defenses can be strong but remains transient. By contrast, life-history shifts can durably and continuously modify the balance between costs and benefits, which arbitrates the evolution of host defenses. Their impact, however, has seldom been documented. Here, we show with a simple mathematical model that the selective advantage of the defense system is expected to decrease with decreasing life span. We further document that, in natural populations of the model plant system Arabidopsis thaliana, the expression level of defense genes correlate positively with flowering time, a proxy for the length of vegetative life span. Using a genetic strategy to partition life span-dependent and –independent defense genes, we demonstrate that this positive co-variation is not explained by the pleiotropic action of major regulatory genes controlling both defense and life span. In agreement with our model, this study reveals that natural selection has likely assembled alleles promoting lower expression of defense genes with alleles decreasing the duration of vegetative life span in natural populations of A. thaliana. This is the first study demonstrating that life history evolution has a pervasive impact on the evolution of host immunity. Overall design: Seeds of Bur-0, Col-0 and 278 Bur-0xCol-0 Recombinant Inbred Lines (RIL) obtained after 8 generations of selfing were provided by the Arabidopsis Stock Center at INRA Versailles (France). We selected the 40 RIL in the 15% and 85% quantiles of flowering time for RNA sequencing. Each RIL and the two parental lines were planted in 20 replicates in the conditions described above. At days 14 and 28, the oldest leaf was flash-frozen in liquid nitrogen. Three pools, each combining 13 RIL, were produced at each time point for early and late lines, for a total of 3 biological replicates, 2 pool types (early and late RIL) and 2 time points (14 and 28 days). For each of the two parental lines, leaves of 12 replicates were pooled for each time point.
Assortment of Flowering Time and Immunity Alleles in Natural Arabidopsis thaliana Populations Suggests Immunity and Vegetative Lifespan Strategies Coevolve.
Specimen part, Subject, Time
View SamplesDifferential gene expression between naive and activated CD8+ T cells was assessed using microarray analysis to determine target genes for new positron emission tomography (PET) probe screening, in particular for molecular imaging of lymphoid organs and immune activation.
Molecular imaging of lymphoid organs and immune activation by positron emission tomography with a new [18F]-labeled 2'-deoxycytidine analog.
No sample metadata fields
View SamplesStudy of the gene expression of T24 bladder cancer cells in response to hypericin-mediated photodynamic therapy in the absence or presence of the p38 MAPK inhibitor PD169316
Molecular effectors and modulators of hypericin-mediated cell death in bladder cancer cells.
Specimen part, Cell line, Compound
View SamplesThe transcriptional response of Arabidopsis thaliana cell suspensions following treatment with the stress hormone methyl jasmonate (MeJA) was monitored over time 16 hours after subcultivation. Three time points were included: 30 minutes, 2 hours and 6 hours after elicitation with 50µm MeJA or DMSO as a control.
Mapping methyl jasmonate-mediated transcriptional reprogramming of metabolism and cell cycle progression in cultured Arabidopsis cells.
Compound, Time
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