Purpose: The ability of adult zebrafish tissues to undergo dedifferentiation provides an opportunity to probe the molecular underpinnings of cell identity and reprogramming. Zebafish muscle regeneration utilizes dedifferentiation to reprogram mature multinucleated myocytes into dedifferentiated myoblast that re-enter the cell cycle. A unique advantage of this system is that the regenerating cell mass is large and fairly homogenous, facilitating genomics approaches to uncovering the underlying biology. Methods: To better understand cellular reprogramming of mature myocytes, we temporally analyzed the changing transcriptome leading up to the proliferative switch. RNA was obtained after Laser Micro-dissection (LMD) of Control, 9 hour post-injury (HPI) or 18 HPI using Trizol and micro column purification. Illumina''s TruSeq Stranded mRNA Library Prep Kit and 0.1 - 4 µg total mRNA from pooled purified RNA samples were used for performing ribosomal-depletion (Ribo-Zero Gold rRNA Removal Kit, Illumina) and library preparation. Sequencing was performed by the UM DNA Sequencing Core, using an Illumina Hi-Seq 2000 (50-cycle, single end read) platform. Results: Clustering and functional annotation of differentially expressed genes highlighted the importance of catabolic and phagocytic processes upregulation at 9 and 18 hours post injury (hpi). Furthermore, genes encoding principle regulators of chromatin states were actively re-regulated during the reprogramming process. Utilizing the accessibility of these tissues in the zebrafish model, kKnockdown experiments enabled in vivo validation and phenotypic analysis of candidate genes and pathways for their roles in genomic and cellular reprogramming. Additionally, we found that despite of their low expression levels, lncRNAs were highly represented in gene clusters with dynamic, “switch-like” expression profiles, and that miRNA processing was also found important for reprogramming Conclusions: We conclude that reprogramming of a “post-mitotic” myocyte into a dedifferentiated myoblast requires both heritable yet nuanced epigenetic alterations and molecular switches that involve transcription factors, miRNA and lncRNA, while maintaining the lineage restriction of the cell of origin. Overall design: Early time points post injury (9 & 18 hours) mRNA and lncRNA profiles of Zebrafish lateral eye muscle (EOM) were generated by deep sequencing, in quadruplicate, using Illumina Hi-seq.
Temporally distinct transcriptional regulation of myocyte dedifferentiation and Myofiber growth during muscle regeneration.
No sample metadata fields
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Genome-wide methylation and expression differences in HPV(+) and HPV(-) squamous cell carcinoma cell lines are consistent with divergent mechanisms of carcinogenesis.
Sex, Age, Specimen part, Cell line
View SamplesOncogenic human papillomaviruses (HPVs) are associated with nearly all carcinomas of the uterine cervix and have also become an increasingly important factor in the etiology of a subset of oropharyngeal tumors. HPV-associated head and neck cancers (HNSCCs) have a distinct risk profile and appreciate a prognostic advantage compared to HPV-negative HNSCC. We analyzed the genome-wide expression patterns in two HPV(+) and two HPV(-) squamous cell carcinoma (SCC) cell lines.
Genome-wide methylation and expression differences in HPV(+) and HPV(-) squamous cell carcinoma cell lines are consistent with divergent mechanisms of carcinogenesis.
Sex, Age, Specimen part, Cell line
View SamplesTo investigate the detailed molecular mechanisms for the regulatory role of Nik in colitis, microarray gene expression analysis was performed on colon tissue RNA isolated from 3-month-old untreated control and DSS treated Nik+/+ and NikIE mice.
Intestinal non-canonical NFκB signaling shapes the local and systemic immune response.
Age
View SamplesThe homeobox containing gene Arx is expressed during ventral telencephalon development and it is required for correct GABAergic interneuron tangential migration from the ganglionic eminences to the olfactory bulbs, cerebral cortex and striatum. Its human ortholog is associated with a variety of neurological clinical manifestations whose syntoms are compatible with a loss of cortical interneurons and altered basal ganglia related-activities in humans. Herein, we reported the identification by global expression profiling of a group of genes whose expression is consistently altered in Arx mutant ganglionic eminences. Following analysis revealed the striking ectopic expression in the ganglionic eminences of a number of genes normally not, or only marginally, expressed in the ventral telencephalon. Among them, we functionally analyzed Ebf3, whose ectopic expression in ventral telencephalon is preventingneuronal tangential migration. Further, we showed that Arx is sufficient to repress Ebf3 endogenous expression and that its silencing in Arx mutant tissue might marginally rescue tangential cell movements. Together, these data provide an initial analysis of the molecular pathways regulated by Arx and how their networking might regulate those specific cellular processes during telencephalon development strongly altered by loss of Arx.
Arx acts as a regional key selector gene in the ventral telencephalon mainly through its transcriptional repression activity.
No sample metadata fields
View SamplesMicroglia colonize the brain parenchyma at early stages of development and accumulate in specific regions where they actively participate in cell death, angiogenesis, neurogenesis and synapse elimination. A recurring feature of embryonic microglial distribution is their association with developing axon tracts which, together with in vitro data, supports the idea of a physiological role for microglia in neurite development. Yet the demonstration of this role of microglia is still lacking. Here, we have studied the consequences of microglial dysfunction on the formation of the corpus callosum, the largest connective structure in the mammalian brain, which shows consistent microglial accumulation during development. We studied two models of microglial dysfunction: the loss-of-function of DAP12, a key microglial-specific signaling molecule, and a model of maternal inflammation by peritoneal injection of LPS at E15.5. We performed transcriptional profiling of maternally inflamed and Dap12-mutant microglia at E17.5. We found that both treatments principally down-regulated genes involved in nervous system development and function, particularly in neurite formation. We then analyzed the functional consequences of these microglial dysfunctions on the formation of the corpus callosum. We also took advantage of the Pu.1-/- mouse line, which is devoid of microglia. We now show that all three models of altered microglial activity resulted in the same defasciculation phenotype. Our study demonstrates that microglia are actively involved in the fasciculation of corpus callosum axons.
Microglia shape corpus callosum axon tract fasciculation: functional impact of prenatal inflammation.
Sex, Specimen part, Treatment
View SamplesWe used microarrays to assess gene expression differences in the hippocampus between FoxO6 mutant and wild-type siblings before (basal) or after novel object learning.
FoxO6 regulates memory consolidation and synaptic function.
Sex, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The Tbr2 Molecular Network Controls Cortical Neuronal Differentiation Through Complementary Genetic and Epigenetic Pathways.
Specimen part
View SamplesThe abscence of TBR2 gene in human leads to microcephaly. This condition is mimicked by the specific ablation of the murine gene in developing cerebral cortex. Herein we compared gene expression in control and Tbr2 cKO in E14.5 cerebral cortices. This approach represents a useful tool to identify the molecular mechanisms at the basis of the phenotype.
The Tbr2 Molecular Network Controls Cortical Neuronal Differentiation Through Complementary Genetic and Epigenetic Pathways.
Specimen part
View SamplesPMID: 15539473. We compared the gene expression in roots between WT and fit mutant under +Fe and -Fe conditions using ATH1 microarray analysis to explore which genes are affected by the loss of FIT function.
The essential basic helix-loop-helix protein FIT1 is required for the iron deficiency response.
Specimen part, Treatment
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