Project description:Patterning and growth are fundamental features of embryonic development that must be tightly coordinated during morphogenesis. While metabolism is known to control cell growth, how it impacts patterning and links to morphogenesis is poorly understood. To understand how metabolism impacts early mesoderm specification during gastrulation, we used in vitro mouse embryonic stem (ES) cell-derived gastruloids, due to ease of metabolic manipulations and high-throughput nature. Gastruloids showed mosaic expression of glucose transporters co-expressing with the mesodermal marker T/Bra. To understand the significance of cellular glucose uptake in development, we used the glucose metabolism inhibitor 2-deoxy-D-glucose (2-DG). 2-DG blocked the expression of T/Bra and abolishes axial elongation in gastruloids. Surprisingly, removing glucose completely from the medium did not phenocopy 2-DG treatment despite a significant decline in glycolytic intermediates occurring under both conditions. As 2-DG can also act as a competitive inhibitor of mannose in protein glycosylation, we added mannose together with 2-DG and found that it could rescue the mesoderm specification. We corroborated these results in vivomouse embryos where supplementing mannose rescued the 2-DG mediated phenotype of mesoderm specification and proximo-distal elongation of the primitive streak. We further showed that blocking production and intracellular recycling of mannose abrogated mesoderm specification. At molecular level, proteomics analysis revealed that mannose reversed glycosylation of the Wnt pathway regulator, Secreted Frizzled Receptor, Frzb, expressed in the primitive streak of the mouse embryo. Our study showed how mannose linked metabolism to glycosylation of a developmental pathway component, crucial in patterning of mesoderm and morphogenesis of gastruloids.
Project description:Mbodj2016 - Mesoderm specification during
Drosophila development
This model is described in the article:
Qualitative Dynamical
Modelling Can Formally Explain Mesoderm Specification and
Predict Novel Developmental Phenotypes.
Mbodj A, Gustafson EH, Ciglar L,
Junion G, Gonzalez A, Girardot C, Perrin L, Furlong EE, Thieffry
D.
PLoS Comput. Biol. 2016 Sep; 12(9):
e1005073
Abstract:
Given the complexity of developmental networks, it is often
difficult to predict the effect of genetic perturbations, even
within coding genes. Regulatory factors generally have
pleiotropic effects, exhibit partially redundant roles, and
regulate highly interconnected pathways with ample cross-talk.
Here, we delineate a logical model encompassing 48 components
and 82 regulatory interactions involved in mesoderm
specification during Drosophila development, thereby providing
a formal integration of all available genetic information from
the literature. The four main tissues derived from mesoderm
correspond to alternative stable states. We demonstrate that
the model can predict known mutant phenotypes and use it to
systematically predict the effects of over 300 new, often
non-intuitive, loss- and gain-of-function mutations, and
combinations thereof. We further validated several novel
predictions experimentally, thereby demonstrating the
robustness of model. Logical modelling can thus contribute to
formally explain and predict regulatory outcomes underlying
cell fate decisions.
This model is hosted on
BioModels Database
and identified by:
MODEL1607310000.
To cite BioModels Database, please use:
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quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Alternative splicing is critical for development. However, its role in the specification of the three embryonic germ layers is poorly understood. By performing RNA-Seq on human embryonic stem cells (hESCs) and derived endoderm, cardiac mesoderm, and ectoderm cell lineages, we detect distinct alternative splicing programs associated with each lineage. The most prominent splicing program differences are observed between definitive endoderm and cardiac mesoderm. Integrative multi-omics analyses link each program with lineage-specific RNA binding protein regulators, and further suggest a widespread role for Quaking (QKI) in the specification of cardiac mesoderm. Remarkably, knockout of QKI disrupts the cardiac mesoderm-associated alternative splicing program and formation of myocytes. These changes likely arise in part through reduced expression of BIN1 splice variants linked to cardiac development. Collectively, our results thus uncover alternative splicing programs associated with the three germ lineages and demonstrate an important role for QKI in the formation of cardiac mesoderm.
Project description:Recent findings suggest that the ribosome itself modulates gene expression. However, whether ribosomes change composition across cell types to control cell fate remains unknown. To determine the magnitude of ribosome heterogeneity and its functional contribution to cell fate specification, we measured ribosomal protein abundance in actively translating ribosomes by quantitative mass spectrometry on a day-by-day basis as human embryonic stem cells differentiate in a step-wise fashion down endoderm and mesoderm lineages. We identified numerous core ribosomal proteins (RPs) as changing significantly in abundance in actively translating ribosomes during cell fate specification, including progressive decreases in ribosome incorporation for several ribosomal proteins during mesoderm differentiation. We further traced ribosome composition changes at the cytoplasmic, whole-cell, and mRNA transcript levels and identified multiple mechanisms regulating actively translating ribosome composition. These findings reveal extensive ribosomal remodeling during differentiation, suggesting that individual ribosomal components may have cell type-specific specialized translation functions.
Project description:AB2.2 cells were subjected to hanging-drop differentiation under normoxia and hypoxia, respectively. RNA-seq were performed at differentiation day 4, when mesoderm markers peaked. Three biological replicates were set for both groups.The expression matrix was obtained by Hisat2 followed by Stringtie.
Project description:Ets transcription factor ER71 is critical for Flk-1 mesoderm specification to different cell lineages. In this dataset, we determine to investigate the mechanisms by which ER71 regulates hematopoietic and endothelial cell versus cardiac cell lineage development. Expression of all four Flk-1+ mesoderm populations (i.e. Er71 overexpressed versus control, Er71 deficient versus control Flk-1+ mesoderm) was compared. Specifically, we sorted Flk-1+ mesoderm from day 3 differentiated embryonic stem(ES) cells, including induced Er71 and control ES cells, as well as Er71+/+ as well as Er71-/- ES cells .
Project description:The Tbx factors Eomesodermin (Eomes) and Brachyury instruct endoderm and mesoderm specification. Both Tbx factors have common large overlap in chromatin binding sites, however their embryonic phenotypes of mutants largely differ. In this study, we delineate the distinct binding patterns and gene target sets of Eomes and Brachyury providing a molecular model of distinct fate specification programs.
Project description:Patterning and growth are fundamental features of embryonic development that must be tightly coordinated during morphogenesis. As metabolism can control cell growth while also providing mechanistic links to developmental signalling pathways, it is ideally placed to enable this coordination. To understand how metabolism impacts early mesoderm specification, we used mouse embryonic stem (ES) cell-derived gastruloids, as these enable temporal control over metabolic manipulations and can be generated in large quantities. Gastruloids show mosaic expression of two glucose transporters,Slc2a1andSlc2a3both of which co-express with the expression of both the mesodermal markerT/Braand the neural markerSox2. To understand the significance of cellular glucose uptake in development, we used the glucose metabolism inhibitor 2-deoxy-D-glucose (2-DG). 2-DG specifically blocks the expression ofT/Brawithout affecting the expression ofSox2and abolishes axial elongation in gastruloids. Surprisingly, removing glucose completely from the medium did not phenocopy 2-DG treatment despite a significant decline in glycolytic intermediates occurring under both conditions. As 2-DG can also act as a competitive inhibitor of mannose, we added mannose together with 2-DG and found that it could rescue the mesoderm specification. Together, our results show that while mannose is crucial for mesoderm specification, the glycolytic pathway is dispensable at early stages ofT/Braexpression in gastruloids.