Gene expression profiling using microarray has been limited to profiling of differentially expressed genes at comparison setting since probesets for different genes have different sensitivities. We overcome this limitation by using a very large number of varied microarray datasets as a common reference, so that statistical attributes of each probeset, such as dynamic range or a threshold between low and high expression can be reliably discovered through meta-analysis. This strategy is implemented in web-based platform named Gene Expression Commons (http://gexc.stanford.edu/ ) with datasets of 39 distinct highly purified mouse hematopoietic stem/progenitor/functional cell populations covering almost the entire hematopoietic system. Since the Gene Expression Commons is designed as an open platform, any scientist can explore gene expression of any gene, search by expression pattern of interest, submit their own microarray datasets, and design their own working models.
Gene Expression Commons: an open platform for absolute gene expression profiling.
Sex, Age
View SamplesDREAM (downstream regulatory element antagonist modulator) is a Ca2+-binding protein that binds DNA and represses transcription in a Ca2+-dependent manner. Previous studies have shown a role for DREAM in cerebellar function regulating the expression of the sodium/calcium exchanger3 (NCX3) in cerebellar granules to control Ca2+ homeostasis and survival of these neurons. To achieve a more global view of the genes regulated by DREAM in the cerebellum, we performed a genome-wide analysis in transgenic cerebellum expressing a Ca2+-insensitive/CREB-independent dominant active mutant DREAM (daDREAM). Our results indicate that DREAM is a major transcription factor in the cerebellum that regulates genes important for cerebellar development.
Reduced Mid1 Expression and Delayed Neuromotor Development in daDREAM Transgenic Mice.
Specimen part
View SamplesChanges in nuclear Ca2+ homeostasis activate specific gene expression programs and are central to the acquisition and the plastic storage of memories. DREAM /KChIP proteins form heterotetramers that bind DNA and repress transcription in a Ca2+-dependent manner. Single ablation of one member of the DREAM/KChIP family may result in a mild or the absence of phenotype due to partial gene compensation. To study the function of DREAM/KChIP proteins in the brain, we used transgenic mice expressing a Ca2+-insensitive/CREB-independent dominant active mutant DREAM (daDREAM). We show that daDREAM controls the expression of several activity-dependent transcription factors including Npas4, Nr4a1, Mef2C, JunB and c-Fos, as well as the chromatin modifying enzyme Mbd4 and proteins related to actin polymerization like Arc and gelsolin. Thus, directly or through these targets, expression of daDREAM in the forebrain resulted in a complex phenotype characterized by i) impaired learning and memory, ii) loss of recurrent inhibition and enhanced LTP in the dentate gyrus without affecting Kv4-mediated potassium currents, and iii) modified spine density in DG granule neurons. Our results propose DREAM as a master-switch transcription factor regulating several activity-dependent gene expression programs to control synaptic plasticity, learning and memory.
DREAM controls the on/off switch of specific activity-dependent transcription pathways.
Specimen part
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