Analysis of hematopoietic stem cells (HSC, LSK Flt3-) and myeloid progenitors (MP, LK CD34+) sorted from wildtype and Dnmt1 hypomorph mice
DNA methylation protects hematopoietic stem cell multipotency from myeloerythroid restriction.
Specimen part
View SamplesEye development and photoreceptor maintenance requires the retinal pigment epithelium (RPE), a thin layer of cells that underlies the neural retina. Despite its importance, RPE development has not been studied by a genomic approach. A microarray expression profiling methodology was established in this study for studying RPE development. The intact retina with RPE attached was dissected from developing embryos, and differentially expressed genes in RPE were inferred by comparing the dissected tissues with retinas without RPE using microarray and statistical analyses. We found 8810 probesets to be significantly expressed in RPE at 52 hours post-fertilization (hpf), of which 1443 might have biologically meaningful expression levels. Further, 78 and 988 probesets were found to be significantly over- or under-expressed in RPE respectively compared to retina. Also, 79.2% (38/48) of the known over-expressed probesets have been independently validated as RPE-related transcripts. The results strongly suggest that this methodology can obtain in vivo RPE specific gene expression from the zebrafish embryos and identify novel RPE markers.
Gene expression profiling of zebrafish embryonic retinal pigment epithelium in vivo.
Specimen part
View SamplesRetinal cells are specified in a zebrafish recessive mutant called young (yng) but they fail to terminally differentiate; i.e. extend neurites and make synaptic contacts. A point mutation in a brahma-related gene 1 (brg1) is responsible for this phenotype. In this microarray study, a three-factor factorial design was utilized to investigate the effects of 1) mutation, 2) change in time (36 vs. 52hpf), and 3) change in tissue (retina vs. whole embryos), and their interactions on gene expression. Significant probesets were inferred by using both specific contrasts of the fitted Analysis of Variance (ANOVA) models and a corresponding 2-fold expression cutoff. The probesets were grouped into three broad categories: 1) Brg1-regulated retinal differentiation genes (731 probsets), 2) Retinal specific genes but independent of Brg1 regulation (3038 probesets) and 3) Genes regulated by Brg1 but outside the retina (107 probesets). Four gene groups/pathways including neurite outgrowth regulators, Delta-Notch signalling molecules, Irx family members and specific cell cycle regulators were identified in the first group, and their relevance for retinal differentiation functionally validated. This study demonstrates that an approach such as ours can identify relevant genes and pathways involved in retinal development as well as the development of other tissues at the same time.
Factorial microarray analysis of zebrafish retinal development.
Specimen part
View SamplesMost metabolic studies are conducted in male animals; thus, the molecular mechanism controlling gender-specific pathways has been neglected, including sex-dependent responses to peroxisome proliferator-activated receptors (PPARs). Here we show that PPARalpha has broad female-dependent repressive actions on hepatic genes involved in steroid metabolism and inflammation. In males, this effect is reproduced by the administration of synthetic PPARalpha ligand. Using the steroid hydroxylase gene Cyp7b1 as a model, we elucidated the molecular mechanism of this PPARalpha-dependent repression. Initial sumoylation of the ligand-binding domain of PPARalpha triggers the interaction of PPARalpha with the GA-binding protein alpha bound to the target promoter. Histone deacetylase is then recruited, and histones and adjacent Sp1-binding site are methylated. These events result in the loss of Sp1-stimulated expression, and thus the down-regulation of Cyp7b1. Physiologically, this repression confers protection against estrogen-induced intrahepatic cholestasis, paving the way for a novel therapy against the most common hepatic disease during pregnancy.
Sumoylated PPARalpha mediates sex-specific gene repression and protects the liver from estrogen-induced toxicity in mice.
No sample metadata fields
View SamplesIdentification of imprinted genes expressed in adult CD3+ splenocytes
Hematopoietic reconstitution with androgenetic and gynogenetic stem cells.
Sex, Age, Specimen part
View SamplesIschemic tolerance can be induced by numerous preconditioning stimuli, including various Toll-like receptor (TLR) ligands. We have shown previously that systemic administration of the TLR4 ligand, lipopolysaccharide (LPS) or the TLR9 ligand, unmethylated CpG ODNs prior to transient brain ischemia in mice confers substantial protection against ischemic damage. To elucidate the molecular mechanisms of preconditioning, we compared brain and blood genomic profiles in response to preconditioning with these TLR ligands and to preconditioning via exposure to brief ischemia.
Multiple preconditioning paradigms converge on interferon regulatory factor-dependent signaling to promote tolerance to ischemic brain injury.
Specimen part, Treatment
View SamplesIn euakryotes, mRNAs must be exported from the nucleus to the cytsoplasm. NXF2 is highly expressed in the mouse male germ cells. We are interested in its function in spermatogenesis, espically in the nuclear RNA export in the testis. To this end, we made Nxf2 mutant mice by gene targeting. In an attempt to identify the mRNA substrates of NXF2, we perform the microarray experiments on testes.
Inactivation of Nxf2 causes defects in male meiosis and age-dependent depletion of spermatogonia.
No sample metadata fields
View SamplesMouse infection with the tapeworm Hymenolepis diminuta leads to a less severe DNBS-colitis. Increased Th2 and regulatory cytokine production in the spleen is a hallmark of Hymenolepis diminuta infection, therefore we hypothesized that given this microenvironment, splenic adaptive cells acquire an anti-inflammatory phenotype. We tested the ability of putative splenic regulatory B cells generated by Hymenolepis diminuta infection to down-regulate intestinal inflammation. We found that unlike splenic B cells from uninfected mice, splenic B cells from Hymenolepis diminuta -infected animals ameliorated chemically-induced colitis.
Splenic B cells from Hymenolepis diminuta-infected mice ameliorate colitis independent of T cells and via cooperation with macrophages.
Specimen part
View SamplesThe goal of the experiment was to determine the transcriptional expression profile of zebrafish thrombocytes in order to enable comparison with mouse and human platelets. Overall design: Thrombocyte isolation from Tg(cd41:EGFP) zebrafish peripheral blood was performed using a novel monoclonal antibody (3H9) to Cd41
Sorting zebrafish thrombocyte lineage cells with a Cd41 monoclonal antibody enriches hematopoietic stem cell activity.
No sample metadata fields
View SamplesIn this study, we generated a zebrafish model of DBA with RPL5 morphants and implemented high-throughput RNA-seq and miRNA-seq to identify key genes, lncRNAs, and miRNAs during zebrafish development and hematopoiesis. We found that RPL5 is required for both primitive and definitive hematopoiesis processes that are partially mediated by the P53 pathway. Several genes such as cirh1a, noc2l, tars, and nol6 and miRNAs such as dre-miR-10a*, dre-miR-722, dre-miR-737, and dre-miR-142a-3p were significantly deregulated, and these changes may play a crucial role in hematopoiesis, ribosome biogenesis and development process. We also characterized the lncRNome in zebrafish with RPL5 deficiency. By constructing a comprehensive regulatory network, we identified central node genes in the network connected to the P53 pathway, almost all of which were targeted by the significantly deregulated miRNAs listed above. Our results therefore establish a regulatory network for critical genes and miRNAs involved in the RPL5-deficient zebrafish model and provide a comprehensive basis for the molecular pathogenesis of RPL5-mediated DBA and other ribosomopathies. Overall design: Determine the differences of transcriptome between RPL5-deficient and MO control zebrafish embryos for understanding the complex molecular pathogenesis of mutant RPL5-mediated human diseases
Transcriptome analysis reveals a ribosome constituents disorder involved in the RPL5 downregulated zebrafish model of Diamond-Blackfan anemia.
No sample metadata fields
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