Nearly all colorectal cancers have dysregulated Wnt signalling, predominantly through the mutation of the Apc (Adenomatous Polyposis Coli) gene. Therefore it is of vital importance to elucidate the key Wnt target genes in intestinal cells in vivo. We have used a novel inducible cre-lox based murine system (designated ApcFlox) to investigate the consequences of perturbation of Wnt signalling following inactivation of Apc in vivo within 100% of the intestinal epithelium. We have employed microarray analysis at 3 time points within our ApcFlox system (Day 3 prior to the onset of phenotype, day 4 the establishment of the phenotype and day 5 gross phenotype of altered proliferation, differentiation and migration) and from adenomas arising in the ApcMin/+ background allowing us characterise Wnt/beta-catenin target genes based on their expression profiles during different stages of intestinal tumourigenesis. Furthermore, we have employed microarray analysis using livers from our ApcFlox system and have demonstrated that there is very little overlap in the Wnt target genes induced by Apc loss in the liver and the intestine. More importantly, we have been able to determine a novel set of putative Wnt/beta-catenin target genes which are upregulated at both early and late stages of tumourigenesis in the intestine and may represent novel therapeutic targets in colon cancer.
Hunk/Mak-v is a negative regulator of intestinal cell proliferation.
Specimen part
View SamplesThe transcription factor Pax6 acts as a key developmental regulator in various organs. In the developing brain Pax6 regulates patterning, neurogenesis and proliferation, but how these diverse effects are mediated at the molecular level is not well understood. As Pax6 regulates forebrain development including neurogenesis, proliferation and patterning, almost exclusively by one of its DNA-binding domains, the bipartite paired domain, we examined the role of its respective DNA-binding subdomains (PAI and RED). Using mice with point mutations in the PAI (Pax6Leca4, N50K) and RED (Pax6Leca2, R128C) subdomains we unravelled opposing roles of mutations in these subdomains in regulating genes that control proliferation in the developing cerebral cortex.
Functional dissection of the paired domain of Pax6 reveals molecular mechanisms of coordinating neurogenesis and proliferation.
Sex
View SamplesSince the discovery of adult neural stem cells, their exact identity is still under discussion. Moreover, the lack of a reproducible procedure to purify neural stem cells prospectively rather than by growing them in vitro has so far precluded their study at the transcriptome level. Here we demonstrate a novel procedure to prospectively isolate neural stem cells from the adult mouse subependymal zone on the basis of their GFAP- and prominin1-expression by fluorescence-activated cell sorting. All self-renewing, multipotent stem cells are contained in this fraction at 70% purity. The stem cell identity of these double-positive cells is further demonstrated in vivo, by using a novel split-Cre-technology for fate mapping.
In vivo fate mapping and expression analysis reveals molecular hallmarks of prospectively isolated adult neural stem cells.
Specimen part
View SamplesWe compared transcriptomes of two ependymoglial populations isolated from adult zebrafish telencephalon. Overall design: Ependymoglial cells are acutely isolated from the adult zebrafish brains form 3 months old transgenic gfap:GFP animals. GFP is experssed in all ependymoglial cells and two populations are separated using GFP intensity in FACS.
The Aryl Hydrocarbon Receptor Pathway Defines the Time Frame for Restorative Neurogenesis.
Specimen part, Subject
View SamplesUnderstanding the mechanisms that specify neuronal subtypes is important to unravel the complex mechanisms of neuronal circuit assembly. Here we have identified a novel role for the transcription factor AP2 in progenitor and neuronal subtype specification in the cerebral cortex. Conditional deletion of AP2 causes misspecification of basal progenitors starting at
AP2gamma regulates basal progenitor fate in a region- and layer-specific manner in the developing cortex.
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View SamplesThe molecular mechanisms of neurogenic fate determination are of particular importance in light of the need to regenerate neurons. However the molecular logic of neurogenic fate determination is still ill understood, even though some key transcription factors have been implicated. Here we describe how one of these, the transcription factor Pax6, regulates adult neurogenesis by initiating a cross-regulatory network of 3 transcription factors executing neuronal fate and regulating genes required for neuronal differentiation. This network is initiated and driven to sufficiently high expression levels by the transcription factor Pax6 in close interaction with Brg1-containing SWI/SNF chromatin remodeling factors.
The BAF complex interacts with Pax6 in adult neural progenitors to establish a neurogenic cross-regulatory transcriptional network.
Sex, Age, Specimen part
View SamplesWe performed microarray experiments with RNAs from dissected immature anthers (stages 4-7) from wild-type, dyt1 and ams mutant plants, using the Affymetrix ATH1 chip.
Regulation of the Arabidopsis anther transcriptome by DYT1 for pollen development.
Specimen part
View SamplesWe used microarray analysis to examine transcriptomic changes in cdm1 mutant, identifying genes potentially regulated by CDM1 by comparing gene expression between cdm1 and wild type young floral buds. Among 375 genes that showed differential expression (P-value <0.05) with >1.5-fold changes between wild type and cdm1, 185 genes were down-regulated by 1.5 to 7.10-folds, whereas 190 genes were up-regulated by 1.5 to 5.82-folds.
The Arabidopsis CALLOSE DEFECTIVE MICROSPORE1 gene is required for male fertility through regulating callose metabolism during microsporogenesis.
Specimen part
View SamplesPurpose: The goal of this study is to evaluate the transcriptome profiling (RNA-seq) of dormant and proliferating breast cancer cells using an in vitro 3D model Methods: mRNA profiles of D2.0R cells growing either on basal membrane extracts (BME) (dormant phase) or BME + Collagen (COL) (proliferative phase) at days 1 or 5 of culture were generated by deep sequencing in triplicate with Ilumina HiSeq2500 using Illumina TruSeq V4. Aligned reads (BAM files) were analysed using PartekFlow software for differential expression and gene enrichment analysis. Comparisons used Partek Gene Specific Analysis (GSA) algorithm and multiple comparisons were corrected using False Discovery Rate (FDR), which was set at 0.05 Results: Using an optimized data analysis workflow, we mapped about 118 – 133 million reads per sample to the mouse genome (build mm9). Total alignment with reference genome is between 81-90%. RNA-seq identified 5,524 transcripts showing differential expression between the D2.0R cells cultured on BME + COL vs D2.0R cells cultured on BME matrices at day 5, with a fold change =1.5 or =-1.5 and p value <0.05. On the other hand, only 1,097 were found to be differentially expressed between D2.0R cells growing on BME matrices at day 5 and day 1, with a fold change =1.5 or =-1.5 and p value <0.05. Hierarchical clustering of differentially expressed genes uncovered several as yet uncharacterized genes that may contribute to breast cancer dormancy and identifies autophagy as a top biological process activated in dormant D2.0R cells. Conclusions: Our study represents a detailed analysis of the transcriptomes of dormant and proliferating D2.0R cells, with three biologic replicates, generated by RNA-seq technology. RNA-seq based transcriptome characterization identifies autophagy as the most prevalent upregulated pathway in dormant breast cancer cells. Overall design: mRNA profiles of D2.0R cells after culture on BME or BME + COL matrices for 1 or 5 days were generated by deep sequencing in triplicate with Ilumina HiSeq2500 using Illumina TruSeq V4.
Autophagy promotes the survival of dormant breast cancer cells and metastatic tumour recurrence.
Specimen part, Subject
View SamplesKMD is genetically engenered to be highly resistant to lepidopteran pests through expressing a synthetic cry1Ab gene and its parent non-transgenic rice is Xiushui 11.The developmental duration of BPH feeding on KMD2 was significantly delayed. And moreover, the fecundity of BPH was significantly lower when fed on Bt rice than on the non-Bt parental plants.To investigate unintended effects in KMD2 that causes changes in BPH performance, we performed microarray (GeneChip) analysis to compare the gene expression profiles between Bt rice and non-transgenic parental plants in response to BPH infestation.
Comparing Gene Expression Profiles Between Bt and non-Bt Rice in Response to Brown Planthopper Infestation.
Specimen part, Treatment
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