The 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.
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View SamplesAntagonism of microRNA-122 in mice by systemically administered LNA-antimiR leads to up-regulation of a large set of predicted target mRNAs in the liver
Antagonism of microRNA-122 in mice by systemically administered LNA-antimiR leads to up-regulation of a large set of predicted target mRNAs in the liver.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Human fetal hemoglobin expression is regulated by the developmental stage-specific repressor BCL11A.
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View SamplesDifferences in the amount of fetal hemoglobin (HbF) that persists into adulthood affect the severity of sickle cell disease and the beta-thalassemia syndromes. Genetic association studies have identified sequence variants in the gene BCL11A that influence HbF levels. Here we examine BCL11A as a potential regulator of HbF expression. The high HbF BCL11A genotype is associated with reduced BCL11A expression. Moreover, abundant expression of full-length forms of BCL11A is developmentally restricted to adult erythroid cells. Down-regulation of BCL11A expression in primary adult erythroid cells leads to robust HbF expression. Consistent with a direct role of BCL11A in globin gene regulation, we find that BCL11A occupies several discrete sites in the beta-globin gene cluster. BCL11A emerges as a therapeutic target for reactivation of HbF in beta-hemoglobin disorders.
Human fetal hemoglobin expression is regulated by the developmental stage-specific repressor BCL11A.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
In vivo mapping of notch pathway activity in normal and stress hematopoiesis.
Sex, Age, Specimen part
View SamplesNotch signaling defines a conserved, fundamental pathway, responsible for determination in metazoan development and is widely recognized as an essential component of lineage specific differentiation and stem cell self-renewal in many tissues including the hematopoietic system. Until recently, the majority of studies in the hematopoietic system focused on Notch signaling in lymphocyte differentiation and knowledge of individual Notch receptor roles in early hematopoiesis has been limited due to a paucity of genetic tools available To fate-map Notch receptor expression and pathway activity in the hematopoietic system we used tamoxifen-inducible CreER knock-in mice for individual Notch receptors in combination to a novel Notch reporter strain (Hes1GFP) and a conditional gain of function allele of Notch2 receptor (Rosa-lsl-ICN2).
In vivo mapping of notch pathway activity in normal and stress hematopoiesis.
Sex, Age, Specimen part
View SamplesNotch signaling defines a conserved, fundamental pathway, responsible for determination in metazoan development and is widely recognized as an essential component of lineage specific differentiation and stem cell self-renewal in many tissues including the hematopoietic system. Until recently, the majority of studies in the hematopoietic system focused on Notch signaling in lymphocyte differentiation and knowledge of individual Notch receptor roles in early hematopoiesis has been limited due to a paucity of genetic tools available To fate-map Notch receptor expression and pathway activity in the hematopoietic system we used tamoxifen-inducible CreER knock-in mice for individual Notch receptors in combination to a novel Notch reporter strain (Hes1GFP) and a conditional gain of function allele of Notch2 receptor (Rosa-lsl-ICN2).
In vivo mapping of notch pathway activity in normal and stress hematopoiesis.
Sex, Specimen part
View SamplesScl/Tal1 confers hemogenic competence and prevents cardiomyogenesis in embryonic endothelium. Here we show that Scl both directly activates a broad gene regulatory network required for hematopoietic stem/progenitor cell (HS/PC) development, and represses transcriptional regulators required for cardiogenesis. Cardiac repression occurs during a short developmental window through Scl binding to distant cardiac enhancers that harbor H3K4me1 at this stage. Scl binding to hematopoietic regulators extends throughout HS/PC and erythroid development and spreads from distant enhancers to promoters. Surprisingly, Scl complex partners Gata 1 and 2 are dispensable for hematopoietic versus cardiac specification and Scl binding to the majority of its target genes. Nevertheless, Gata factors co-operate with Scl to activate selected transcription factors to facilitate HS/PC emergence from hemogenic endothelium. These results uncover a dual function for Scl in dictating hematopoietic versus cardiac fate choice and suggest a mechanism by which lineage-specific bHLH factors direct the divergence of competing fates.
Scl binds to primed enhancers in mesoderm to regulate hematopoietic and cardiac fate divergence.
Specimen part, Cell line
View SamplesThe goal was to identify genes targeted by miR-30a.
The microRNA-30 family is required for vertebrate hepatobiliary development.
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View SamplesEndothelium in embryonic hematopoietic tissues generates hematopoietic stem/progenitor cells; however, it is unknown how its unique potential is specified. We show that transcription factor Scl/Tal1 is essential for both establishing the hematopoietic transcriptional program in hemogenic endothelium and preventing its misspecification to a cardiomyogenic fate. Scl-/- embryos activated a cardiac transcriptional program in yolk sac endothelium, leading to the emergence of CD31+Pdgfr+ cardiogenic precursors that generated spontaneously beating cardiomyocytes. Ectopic cardiogenesis was also observed in Scl-/- hearts, where the disorganized endocardium precociously differentiated into cardiomyocytes. Induction of mosaic deletion of Scl in Sclfl/flRosa26Cre-ERT2 embryos revealed a cell-intrinsic, temporal requirement for Scl to prevent cardiomyogenesis from endothelium. Scl-/- endothelium also upregulated the expression of Wnt antagonists, which promoted rapid cardiomyocyte differentiation of ectopic cardiogenic cells. These results reveal unexpected plasticity in embryonic endothelium such that loss of a single master regulator can induce ectopic cardiomyogenesis from endothelial cells.
Scl represses cardiomyogenesis in prospective hemogenic endothelium and endocardium.
Specimen part
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