Project description:Comparison of the RNA-expression pattern of Pax5-deficient progenitor-cell tumors with wild-type pro-B-cells Keywords: Genetic modification
Project description:We created mice, which are deficient for Myc specifically in cardiac myocytes by crossing crossed Myc-floxed mice (Mycfl/fl) and MLC-2VCre/+ mice. Serial analysis of earlier stages of gestation revealed that Myc-deficient mice died prematurely at E13.5-14.5. Morphological analyses of E13.5 Myc-null embryos showed normal ventricular size and structure; however, decreased cardiac myocyte proliferation and increased apoptosis was observed. BrdU incorporation rates were also decreased significantly in Myc-null myocardium. Myc-null mice displayed a 3.67-fold increase in apoptotic cardiomyocytes by TUNEL assay. We examined global gene expression using oligonucleotide microarrays. Numerous genes involved in mitochondrial death pathways were dysregulated including Bnip3L and Birc2. Keywords: wildtype vs Myc-null
Project description:Pax5 is a critical regulator of B cell commitment. Here we identified direct Pax5 target genes by streptavidin-mediated ChIP-chip analysis of pro-B cells expressing in vivo biotinylated Pax5. By binding to promoters and enhancers, Pax5 directly regulates the expression of multiple transcription factor, cell surface receptor and signal transducer genes. One of the newly identified enhancers was shown by transgenic analysis to confer Pax5-dependent B-cell-specific activity to the Nedd9 gene controlling B cell trafficking. Profiling of histone modifications in Pax5-deficient and committed wild-type pro-B cells demonstrated that Pax5 induces active chromatin at activated target genes, while eliminating active chromatin at repressed genes in committed pro-B cells. Pax5 rapidly induces these chromatin and transcription changes by recruiting chromatin-remodeling, histone-modifying and basal transcription factor complexes to its target genes. These data provide novel insight into the regulatory network and epigenetic regulation, by which Pax5 controls B cell commitment. Analysis of chromatin and TF binding in rag2-/- and pax5-/- rag2-/- pro-B cells. Chip-Chip with 1-3 experiments for each antibody and celltype combination.
Project description:STAT5 and IL-7 signaling are thought to control B-lymphopoiesis by regulating key transcription factor genes and activating VH gene segments at the Igh locus. Using conditional mutagenesis, we demonstrate that transgenic Bcl2 expression rescued the development of Stat5-deleted pro-B cells by compensating for the loss of Mcl-1. Ebf1 and Pax5 expression as well as VH recombination were normal in Bcl2-rescued pro-B cells lacking STAT5 or IL-7Ra. In agreement with this finding, STAT5-expressing pro-B cells contained little or no active chromatin at most VH genes. In contrast, Igk rearrangements were increased in STAT5- or IL-7Ra-deficient pro-B cells, consistent with direct binding of STAT5 to the intronic iEk enhancer in wild-type pro-B cells. Hence, STAT5 and IL-7 signaling control cell survival and suppress premature Igk recombination in early B-lymphopoiesis. comparison of wt vs Rag2-/- pro-B cells
Project description:The transcription factor Pax5 represses B-lineage-inappropriate genes and activates B-cell-specific genes in B-lymphocytes. Here we have identified 170 novel Pax5-activated genes. Conditional mutagenesis demonstrated that the Pax5-regulated genes require continuous Pax5 activity for normal expression in pro-B and mature B cells. Expression of half of the Pax5-activated genes is either absent or significantly reduced upon Pax5 loss in plasma cells. Direct Pax5 target genes were identified based on their protein synthesis-independent activation by a Pax5-estrogen receptor fusion protein. Chromatin immunoprecipitation (ChIP) of Pax5 together with chromatin profiling by ChIP-on-chip analysis demonstrated that Pax5 directly activates the chromatin at promoters or putative enhancers of Pax5 target genes. The novel Pax5-activated genes code for key regulatory and structural proteins involved in B cell signaling, adhesion, migration, antigen presentation and germinal center B cell formation, thus revealing a complex regulatory network, which is activated by Pax5 to control B cell development and function. Keywords: Chip-chip, cell type comparison comparison of Pax5-/-Rag2-/- vs Rag2-/- pro-B cells