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GSE20204
Anopheles gambiae
6 Downloadable Samples
Affymetrix Plasmodium/Anopheles Genome Array (plasmodiumanopheles)
Description
The Anopheles gambiae midgut harbors bacteria that proliferate upon a blood feed. We used microarrays to examine the midgut gene expression response at early stages (3hours) after an artifitial meal containing heat killed bacteria.
Publication Title
A peroxidase/dual oxidase system modulates midgut epithelial immunity in Anopheles gambiae.
Sample Metadata Fields
Age, Specimen part
View Samples- Homo sapiens
- 43 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Integration of multiple signals shapes cell adaptation to their microenvironment through synergistic and antagonistic interactions. The combinatorial complexity governing signal integration for multiple cellular output responses has not been resolved. For outputs measured in the conditions 0 (control), signals X, Y, X+Y, combinatorial analysis revealed 82 possible interaction profiles, which we biologically assimilated to 5 positive, and 5 negative interaction modes. To experimentally validate their use in living cells, we designed an original computational workflow, and applied it to transcriptomics data of innate immune cells integrating physiopathological signal combinations. Up to 9 of the 10 defined modes coexisted in context-dependent proportions. Each integration mode was enriched in specific molecular pathways, suggesting a coupling between genes involved in particular functions, and the corresponding mode of integration. We propose that multimodality and functional coupling are general principles underlying the systems level integration of physiopathological and pharmacological stimuli by mammalian cells.
Publication Title
Combinatorial code governing cellular responses to complex stimuli.
Sample Metadata Fields
Time
View Samples- Mus musculus
- 2 Downloadable Samples
Illumina HiSeq 2000
Description
Long interspersed elements 1 (LINE-1 or L1) are retrotransposons that dominate the mouse genomic landscape, and are expressed in Embryonic Stem Cells (ESCs), germ cells, and during early development. Based on clear precedents in plants and fission yeast, we investigated in this study a role for RNAi and other RNA degradation pathways in the regulation of L1 expression and mobilization. We uncovered the existence of novel small (s)RNAs that map to active L1 elements. Some of these sRNAs have characteristics of cognate short-interfering RNA populations, while others display length heterogeneity that evokes a biogenesis through a RNA surveillance pathway, in a Dicer-independent manner. We additionally found that genetic ablation of Dicer and the sRNA effector protein AGO2 has complex and profound consequences on L1 transcription and mobilization in ESCs, indicating that endogenous RNA interference (RNAi) pathway indeed maintain genomic integrity against L1 proliferation. Finally, we investigated the implication of L1 retrotransposition during ESC differentiation and propose that the mobilization of L1 elements in Dicer mutant ESCs could partially explain the inability of these cells to differentiate. Overall design: 2 samples examined: WT E14 and Dicer mutant mouse ESCs
Publication Title
RNAi-dependent and independent control of LINE1 accumulation and mobility in mouse embryonic stem cells.
Sample Metadata Fields
Specimen part, Subject
View Samples- Mus musculus
- 60 Downloadable Samples
- Illumina HiSeq 2000
Description
Xist is indispensable for X chromosome inactivation (XCI) in female mammalian cells. However, how Xist RNA directs chromosome-wide transcriptional inactivation of the X chromosome is largely unknown. Here, to study chromosome inactivation by Xist, we generated a system where ectopic Xist expression can be induced from several genomic contexts in aneuploid mouse ES cells. We found that ectopic Xist expression from any location on the X chromosome faithfully recapitulated endogenous XCI, showing the potency of Xist to initiate XCI. Genes that escape XCI remain consistently transcriptionally active upon ectopic XCI, regardless of their position relative to Xist transgenes, and the enrichment of CTCF at their promoters is implicated in directing XCI escape. Xist expression from autosomes facilitates their transcriptional silencing to different degrees, and gene density in proximity of the Xist transcription locus plays a central role in determining the efficiency of gene inactivation. We also show that the enrichment of LINE elements together with a specific chromatin environment facilitates Xist-mediated silencing of both X-linked and autosomal genes. These findings provide new insights into the epigenetic mechanisms that mediate XCI and identify genomic features that promote Xist-mediated chromosome-wide gene inactivation Overall design: 60 RNA-seq from mouse embryonic stem cells and fully differentiated neurons in which ectopic Xist epression is either triggered (plus samples) or not (minus samples) upon doxycycline treatment.
Publication Title
Genetic and epigenetic features direct differential efficiency of Xist-mediated silencing at X-chromosomal and autosomal locations.
Sample Metadata Fields
Sex, Specimen part, Cell line, Subject
View Samples- Mus musculus
- 16 Downloadable Samples
- Illumina HiSeq 2500
Description
How the parental genomes of the very specialized sperm and oocyte cells are remodelled upon fertilization to confer totipotency has remained a tantalizing open questions. Indeed, in the case of mammals, the parental genomes undergo dramatic reprogramming upon fertilization, including differential dynamics of histone post-translational modifications. The roles of histone modifying enzymes in this process, which are maternally provided, are only just starting to emerge. Here, we explore the function of the oocyte inherited pool of Lsd1/Kdm1a, which encodes a histone H3K4 and K9 demethylase, during early mouse development. Maternal deficiency of Lsd1/Kdm1a results in developmental arrest by the two-cell stage, associated with dramatic and stepwise alterations in H3K9 and H3K4 methylation patterns depending on its demethylase activity. At the transcriptional level, two major changes occur. On one hand, switch from maternal-to-zygotic program fails to be induced. On the other hand, LINE-1 retrotransposons are not properly silenced, along with evidences for increased LINE-1 activity. We propose that Lsd1/Kdm1a is involved in the correct establishment of epigenetic information harboured by histones and is involved in the initiation of new pattern of genome expression driving early mouse development and preserving genome integrity Overall design: RNA-seq of invidual mouse two-cell stage embryos
Publication Title
Maternal LSD1/KDM1A is an essential regulator of chromatin and transcription landscapes during zygotic genome activation.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 14 Downloadable Samples
- Illumina HiSeq 2500
Description
How the parental genomes of the very specialized sperm and oocyte cells are remodelled upon fertilization to confer totipotency has remained a tantalizing open questions. Indeed, in the case of mammals, the parental genomes undergo dramatic reprogramming upon fertilization, including differential dynamics of histone post-translational modifications. The roles of histone modifying enzymes in this process, which are maternally provided, are only just starting to emerge. Here, we explore the function of the oocyte inherited pool of Lsd1/Kdm1a, which encodes a histone H3K4 and K9 demethylase, during early mouse development. Maternal deficiency of Lsd1/Kdm1a results in developmental arrest by the two-cell stage, associated with dramatic and stepwise alterations in H3K9 and H3K4 methylation patterns depending on its demethylase activity. At the transcriptional level, two major changes occur. On one hand, switch from maternal-to-zygotic program fails to be induced. On the other hand, LINE-1 retrotransposons are not properly silenced, along with evidences for increased LINE-1 activity. We propose that Lsd1/Kdm1a is involved in the correct establishment of epigenetic information harboured by histones and is involved in the initiation of new pattern of genome expression driving early mouse development and preserving genome integrity Overall design: RNA-seq of invidual mouse oocytes
Publication Title
Maternal LSD1/KDM1A is an essential regulator of chromatin and transcription landscapes during zygotic genome activation.
Sample Metadata Fields
Cell line, Subject
View Samples- Homo sapiens
- 39 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Medulloblastoma is the most frequent malignant pediatric brain tumor. Considerable efforts are dedicated to identify markers that help to refine treatment strategies. The activation of the Wnt/beta-catenin pathway occurs in 10-15% of medulloblastomas and has been recently described as a marker for favorable patient outcome. We report a series of 72 pediatric medulloblastomas evaluated for beta-catenin immunostaining, CTNNB1 mutations, and studied by comparative genomic hybridization. Gene expression profiles were also available in a subset of 40 cases. Immunostaining of beta-catenin showed extensive nuclear staining (>50% of the tumor cells) in 6 cases and focal nuclear staining (<10% of cells) in 3 cases. The other cases exhibited either a signal strictly limited to the cytoplasm (58 cases) or were negative (5 cases). CTNNB1 mutations were detected in all beta-catenin extensively nucleopositive cases. The expression profiles of these cases documented a strong activation of the Wnt/beta-catenin pathway. Remarkably, 5 out of these 6 tumors showed a complete loss of chromosome 6. In contrast, cases with focal nuclear beta-catenin staining, as well as tumors with negative or cytoplasmic staining, never demonstrated CTNNB1 mutation, Wnt/beta-catenin pathway activation or chromosome 6 loss. Patients with extensive nuclear staining were significantly older at diagnosis and were in continuous complete remission after a mean follow-up of 75.7 months (range 27.5-121.2) from diagnosis. All three patients with a focal nuclear staining of beta-catenin died within 36 months from diagnosis. Altogether, these data confirm and extend previous observations that CTNNB1-mutated tumors represent a distinct molecular subgroup of medulloblastomas with favorable outcome, indicating that therapy de-escalation should be considered. Yet, international consensus on the definition criteria of this distinct medulloblastoma subgroup should be achieved.
Publication Title
Beta-catenin status in paediatric medulloblastomas: correlation of immunohistochemical expression with mutational status, genetic profiles, and clinical characteristics.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Introduction
Publication Title
Frequent PTEN genomic alterations and activated phosphatidylinositol 3-kinase pathway in basal-like breast cancer cells.
Sample Metadata Fields
Sex, Disease stage
View Samples- Homo sapiens
- 45 Downloadable Samples
- Affymetrix Human Exon 1.0 ST Array [CDF: Brainarray Version 13.0 (huex10st)
Description
We compare the genetic profiles of the primary tumors of uveal melanoma or metastasis to their corresponding xenografts that have been passaged over time.
Publication Title
Patient-derived xenografts recapitulate molecular features of human uveal melanomas.
Sample Metadata Fields
Disease
View Samples- Homo sapiens
- 63 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
A high percentage of uveal melanoma patients develop metastatic tumors that predominately occur in the liver. To identify genes associated with metastasis in this pathology, we studied 63 molecular profiles derived from gene expression microarrays performed from enuceated primary tumors.
Publication Title
High PTP4A3 phosphatase expression correlates with metastatic risk in uveal melanoma patients.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples