Project description:In this study, we interrogated the role of DNA methylation in HSPC generation by taking advantage of dnmt1 knockout/knockdown embryos in zebrafish. First, we generated a comprehensive DNA methylation landscape of EHT, which revealed gradually hypermethylated regions associated with vasculogenesis. Taking advantage of dnmt1-deficient embryos, we showed that the decreased DNA methylation blocked HSPC emergence. Mechanistically, we demonstrated that the decreased DNA methylation increased the expression of arterial genes and Notch signaling, thus contributing to defects in the EHT in dnmt1-deficient embryos. Herein, we identified that DNA methylation, as epigenetic regulator, participates in the negative modulation of Notch signaling through inhibiting transcription during HSPC generation in zebrafish.
Project description:Zebrafish (Danio rerio) model system have used widespread vertebrate investigations for genetic and cell biological analyses, and is suitable for small molecular screens such as chemical, toxicity and drug in order to use for human diseases and drug discovery . Recently, These powerful zebrafish model increasingly apply to human metabolic disease such as obesity and diabetes and toxicology. Despite a lot of advantages, proteomics research at zebrafish has received little interest in comparison with genetic and biological research using histology and in situ hybridization. Protein lysine acetylation is one of the most known post-translational modifications with dynamic and reversibly controlled by lysine acetyltransferase such as histone acetyltransferases and lysine deacetylase such as histone deacetylases and sirtuins family.Also, during the past year, global lysine acetylome studies using MS-based proteomics approach was in diverse species such as human, mouse, E. coli, Yeast and plants. Based on global acetylome data, our understanding of the roles of lysine acetylation in various cellular processes has increased. . The aim of this study was to identify Lysine acetylation in zebrafish embryos and determine the homology from Human at modified site level. Here we showed the global lysine acetylation study in Zebrafish embryos using MS-based zebrafish embryos.
Project description:Signaling pathways controlling vasculogenesis and angiogenesis are still poorly understood. Zebrafish Ets1-related protein (Etsrp) which encodes an ETS domain transcription factor, evolutionary related to the mammalian ER71 protein subfamily, has been identified as a major regulator of vasculogenesis and myelopoiesis and functions at the hemangioblast stage affecting the formation of both lineages. In the absence of Etsrp, angioblasts do not migrate or differentiate while overexpression of Etsrp results in the expansion of vascular endothelial and myeloid lineages. To identify genes functioning downstream of Etsrp we performed microarray analysis of etsrp-overexpressing embryos. Etsrp RNA injected embryos and control uninjected embryos were frozen at the tailbud stage and analyzed for expression of more than 30,000 genes using Nimblegen expression arrays. Approximately 300 genes showed greater than two-fold induction in etsrp-overexpressing embryos. Scl, crl, egfl7, aqp8, fli1a, fli1b, lmo2, cdh5 were among the previously known hemangioblast or vasculature-specific genes which were strongly upregulated in Etsrp-overexpressing embryos. We isolated and characterized a number of genes that were novel or previously unassociated with the zebrafish vasculature formation. Eight of them which include angiotensin II type 2 receptor (agtr2), src homology 2 domain containing E (she), similar to mannose receptor C1 (mrc1), endothelial cell-specific adhesion molecule (esam), cdc42 guanine nucleotide exchange factor 9 (arhgef9), yes-related kinase (yrk), zinc finger protein, multitype 2b (zfpm2b/fog2b) and stabilin 2 (stab2) were specifically expressed in vascular endothelial cells during early embryonic development while keratin18 expression was localized to the myeloid cells among others. Identification of novel vasculature and myeloid-specific genes that are regulated by Etsrp will be important for dissecting molecular mechanisms that regulate vasculogenesis / angiogenesis and myelopoiesis.
Project description:Dieldrin is a legacy pesticide that has multiple modes of action (MOA) that include being an estrogen receptor agonist, GABA receptor antagonist, and a chemical that disrupts mitochondrial function. There is also evidence that dieldrin exposure is significantly associated with an increased risk for neurodegeneration in humans. The objective of this thesis was to clarify the effects of dieldrin in the hypothalamus, the major neuroendocrine region of the brain, in the zebrafish (Danio rerio). Zebrafish were fed pellets containing 0.03, 0.15, or 1.8 µg/g dieldrin for 21 days and a global gene expression analysis was performed to characterize cellular processes and pathways affected by dieldrin.
Project description:The exon junction complex (EJC) is composed of three core proteins Rbm8a, Magoh and Eif4a3 and is thought to play a role in several post-transcriptional processes. In this study we focus on understanding the role of EJC in zebrafish development. We identified transcriptome-wide binding sites of EJC in zebrafish via RNA:protein immunoprecipitation followed by deep sequencing (RIP-Seq). We find that, as in human cells, zebrafish EJC is deposited about 24 nts upstream of exon-exon junctions. We also identify transcripts regulated by Rbm8a and Magoh in zebrafish embryos using whole embryo RNA-seq from rbm8a mutant, magoh mutant and wild-type sibling embryos. This study shows that nonsense mediated mRNA decay is dysregulated in zebrafish EJC mutants.
Project description:Histidine phosphorylation is a reversible post-translational modification that is known to regulate signal transduction in prokaryotes. In an effort to help elucidate the heretofore hidden vertebrate phosphoproteome, this report presents a global phosphorylation analysis of Danio rerio (zebrafish) larvae. Phosphopeptide enrichment was performed using a TiO2 affinity technique. A total of 68 unique phosphohistidine sites were detected on 63 proteins among 1076 unique phosphosites on 708 proteins. This report provides the first phosphohistidine dataset obtained from zebrafish.
Project description:Domesticated animal populations often show profound reductions in predator avoidance and fear-related behavior compared to wild populations. These reductions are remarkably consistent and have been observed in a diverse array of taxa including fish, birds, and mammals. Experiments conducted in common environments indicate that these behavioral differences have a genetic basis. In this study, we quantified differences in fear-related behavior between wild and domesticated zebrafish strains and used microarray analysis to identify genes that may be associated with this variation. Compared to wild zebrafish, domesticated zebrafish spent more time near the water surface and were more likely to occupy the front of the aquarium nearest a human observer. Microarray analysis of the brain transcriptome identified high levels of population variation in gene expression, with 1,749 genes significantly differentially expressed among populations. Genes that varied among populations belonged to functional categories that included DNA repair, DNA photolyase activity, response to light stimulus, neuron development and axon guidance, cell death, iron-binding, chromatin reorganization, and homeobox genes. Comparatively fewer genes (112) differed between domesticated and wild strains with notable genes including gpr177 (wntless), selenoprotein P1a, synaptophysin and synaptoporin, and acyl-CoA binding domain containing proteins (acbd3 and acbd4). Microarray analysis identified a large number of genes that differed among zebrafish populations and may underlie behavioral domestication. Comparisons with similar microarray studies of domestication in rainbow trout and canids identified sixteen evolutionarily or functionally related genes that may represent components of shared molecular mechanisms underlying convergent behavioral evolution during vertebrate domestication. However, this conclusion must be tempered by limitations associated with comparisons among microarray studies and the low level of population-level replication inherent to these studies.