Scl/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 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
View SamplesThe onset of the liver inflamentation in the Sox17+/- embryos.
Sox17 haploinsufficiency results in perinatal biliary atresia and hepatitis in C57BL/6 background mice.
Specimen part
View SamplesOne of the central issues in evolutionary developmental biology is how we can formulate the relationships between evolutionary and developmental processes. Two major models have been proposed: the 'funnel-like' model, in which the earliest embryo shows the most conserved morphological pattern, followed by diversifying later stages, and the 'hourglass' model, in which constraints are imposed to conserve organogenesis stages, which is called the phylotypic period. Here we perform a quantitative comparative transcriptome analysis of several model vertebrate embryos and show that the pharyngula stage is most conserved, whereas earlier and later stages are rather divergent. These results allow us to predict approximate developmental timetables between different species, and indicate that pharyngula embryos have the most conserved gene expression profiles, which may be the source of the basic body plan of vertebrates.
Comparative transcriptome analysis reveals vertebrate phylotypic period during organogenesis.
Sex, Specimen part, Disease, Disease stage
View SamplesTranscription profiling of mouse development
Comparative transcriptome analysis reveals vertebrate phylotypic period during organogenesis.
Sex, Specimen part, Disease, Disease stage
View SamplesOur study in zebrafish is the first to use an animal model to understand the biology of the developmental disorder Roberts Syndrome (RBS). RBS is caused by mutations in the ESCO2 gene.
A zebrafish model of Roberts syndrome reveals that Esco2 depletion interferes with development by disrupting the cell cycle.
Age, Specimen part
View SamplesThe generation of properly functioning gametes in vitro, a key goal in developmental/reproductive biology, requires multi-step reconstitutions of complex germ cell development. Based on the logic of primordial germ cell (PGC)-specification, we demonstrate here the generation of PGC-like cells (PGCLCs) in mice with robust capacity for spermatogenesis from embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) through epiblast-like cells (EpiLCs), a cellular state highly similar to pre-gastrulating epiblasts, but distinct from epiblast stem cells (EpiSCs). The global transcription profiles, epigenetic reprogramming, and cellular dynamics during PGCLC induction from EpiLCs are a meticulous capture of those associated with PGC specification from the epiblasts. Furthermore, we identify Integrin-beta 3 and SSEA1 as markers that purify PGCLCs with spermatogenic capacity free from tumorigenic undifferentiated cells. With the reconstitution of PGC specification pathway from the naive inner cell mass state, our study defines a paradigm for the essential step of in vitro gametogenesis.
Reconstitution of the mouse germ cell specification pathway in culture by pluripotent stem cells.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Sox11 prevents tumorigenesis of glioma-initiating cells by inducing neuronal differentiation.
Specimen part, Cell line
View SamplesFollowing the identification of a critical time window of Blood Brain Barrier formation in the mouse embryo, we aimed to identify genes important for barriergenesis. To this end, we isolated cortical and lung E13.5 endothelial cells and compared expression between the two populations.
Mfsd2a is critical for the formation and function of the blood-brain barrier.
Specimen part
View SamplesTo identify factors involved in tumorigenicity of glioma-initiating cells (GICs), we compared gene expression in GIC-like cells with and without sox11 expression.
Sox11 prevents tumorigenesis of glioma-initiating cells by inducing neuronal differentiation.
Specimen part, Cell line
View Samples