Mus musculus
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ABSTRACT:
PROVIDER: PRJNA118213 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The number of vertebrae is strictly defined for any given species1, and depends on the number of somites, which are periodically formed as perfectly matched cell masses during mid-embryogenesis, where the somite segmentation clock prescribes the timing2. The tempo of the clock is affected by surrounding condition, despite which the same number of somites is formed3, suggesting that the clock may be tunable to adapt to the environmental condition. Here, we demonstrate a tunability of the segmentation clock in the period depending on the level of Notch signaling that senses the surrounding information to adjust the number of somites and vertebrae precisely, in which we propose a mechanism of the clock with a feedback loop of Notch signaling by Notch-regulated ankyrin repeat protein (Nrarp). Disruption of Nrarp in mouse resulted in the loss of two vertebrae, due to 4-min extension of the period of the clock elicited by the up-regulation of Notch activity, whereas pharmacological diminishment of Notch activity shortens it by a few min. The Notch inhibitor rescues the phenotype of Nrarp knockout mice in the period. These results are comprehended by mathematical analyses, in which the period of the clock is fine-tuned by Notch activity that Nrarp adjusts. Overall, our results are the first to provide molecular evidence of fine-tuning of the segmentation clock that preserves the number of somites and vertebrae.
2010-10-01 | GSE18419 | GEO
Project description:The number of vertebrae is strictly defined for any given species1, and depends on the number of somites, which are periodically formed as perfectly matched cell masses during mid-embryogenesis, where the somite segmentation clock prescribes the timing2. The tempo of the clock is affected by surrounding condition, despite which the same number of somites is formed3, suggesting that the clock may be tunable to adapt to the environmental condition. Here, we demonstrate a tunability of the segmentation clock in the period depending on the level of Notch signaling that senses the surrounding information to adjust the number of somites and vertebrae precisely, in which we propose a mechanism of the clock with a feedback loop of Notch signaling by Notch-regulated ankyrin repeat protein (Nrarp). Disruption of Nrarp in mouse resulted in the loss of two vertebrae, due to 4-min extension of the period of the clock elicited by the up-regulation of Notch activity, whereas pharmacological diminishment of Notch activity shortens it by a few min. The Notch inhibitor rescues the phenotype of Nrarp knockout mice in the period. These results are comprehended by mathematical analyses, in which the period of the clock is fine-tuned by Notch activity that Nrarp adjusts. Overall, our results are the first to provide molecular evidence of fine-tuning of the segmentation clock that preserves the number of somites and vertebrae. Nrarp mutant mouse which have LacZ gene instead of Nrarp coding region was generated by homologous recombinant. Fragnant female heterozygous mutant mice, mated with heterozygous mutant male, were dissected at embryonic day 10.5 (E10.5). 12 PSMs were collected in each genotype to extract total RNA.
2010-10-01 | E-GEOD-18419 | biostudies-arrayexpress
Project description:All vertebrates share a segmented body axis. Segments form from the rostral end of the presomitic mesoderm (PSM) with a periodicity that is regulated by the segmentation clock. The segmentation clock is a molecular oscillator that exhibits dynamic clock gene expression across the PSM with a periodicity that matches somite formation. Notch signalling is crucial to this process. Altering Notch intracellular domain (NICD) stability affects both the clock period and somite size. However, the mechanism by which NICD stability is regulated in this context is unclear. We identified a highly conserved site crucial for NICD recognition by the SCF E3 ligase, which targets NICD for degradation. We demonstrate both CDK1 and CDK2 can phosphorylate NICD in the domain where this crucial residue lies and that NICD levels vary in a cell cycle-dependent manner. Inhibiting CDK1 or CDK2 activity increases NICD levels both in vitro and in vivo, leading to a delay of clock gene oscillations and an increase in somite size.
2020-03-24 | PXD013038 | Pride
Project description:The number of vertebrae is precisely defined in almost all vertebrate species, but varies considerably in pigs, making this animal an excellent model for studying the mechanisms that control vertebral number. Vertnin (VRTN) variants have been associated with thoracic vertebral number (TVN) in pigs. However, the causal relation between VRTN and TVN remains to be established, and the role of VRTN in modulating TVN is not yet known. Here, we demonstrate that VRTN is one of the genes responsible for determining TVN. We show that VRTN is a DNA-binding transcription factor, which is essential for the formation of thoracic vertebrae during early embryogenesis as VRTN-null mice showed embryonic lethality at the later thoracic somite stages and had fewer somites than their wild-type and heterozygous littermates. We also show that VRTN causative variants increase Notch signaling in pig embryos, suggesting that VRTN controls segment number by altering the pace of somatic segmentation. These findings advance our understanding of the role of VRTN in the formation of thoracic vertebrae and reveal new aspects of somite developmental biology.
2019-10-09 | GSE87775 | GEO
Project description:The number of vertebrae is precisely defined in almost all vertebrate species, but varies considerably in pigs, making this animal an excellent model for studying the mechanisms that control vertebral number. Vertnin (VRTN) variants have been associated with thoracic vertebral number (TVN) in pigs. However, the causal relation between VRTN and TVN remains to be established, and the role of VRTN in modulating TVN is not yet known. Here, we demonstrate that VRTN is one of the genes responsible for determining TVN. We show that VRTN is a DNA-binding transcription factor, which is essential for the formation of thoracic vertebrae during early embryogenesis as VRTN-null mice showed embryonic lethality at the later thoracic somite stages and had fewer somites than their wild-type and heterozygous littermates. We also show that VRTN causative variants increase Notch signaling in pig embryos, suggesting that VRTN controls segment number by altering the pace of somatic segmentation. These findings advance our understanding of the role of VRTN in the formation of thoracic vertebrae and reveal new aspects of somite developmental biology.
2019-10-09 | GSE87774 | GEO
Project description:Little is known about human segmentation clock during somitogenesis. Human embryonic stem (ES) cell differentiation towards PSM and somite cells provide a window of opportunity to probe for the dynamics of oscillatory gene expression. Using high temporal RNA-seq, we captured a transcriptional signature highly reminiscent of segmentation clock during somite differentiation. Our study provides a novel in vitro system to model human segmentation clock that is otherwise inaccessible during development.
2019-08-27 | GSE128469 | GEO
Project description:Within a given vertebrate species, the total number of vertebrae in each anatomical domain is precisely defined and shows little variation among individuals. In contrast, this number can vary tremendously between different species, ranging from as few as six vertebrae in frogs to as many as several hundred in some snakes and fish. Segmental precursors of the vertebrae, called somites are produced sequentially in the embryo from the presomitic mesoderm (PSM), until a final number characteristic of the species, is reached. Here, we show in the chicken embryo that, by controlling the rate of axis elongation, Hox genes control the total number of somites generated by the embryo. We observed that activation of the most posterior Hox genes in somite precursors of the tail bud correlates with an abrupt slowing-down of the speed of axis elongation. We show that progressively more posterior Hox genes, which are collinearly activated in somitic precursors of the epiblast, repress Wnt activity with increasing strength. This leads to a graded repression of the Brachyury/T transcription factor, reducing mesoderm ingression and slowing down the elongation process. Due to the continuation of somite formation, the PSM, which is not fed with sufficient supply of new cells posteriorly, becomes progressively exhausted, ultimately leading to an arrest of segment formation. Our data provide a conceptual framework to explain how the cross-talk between the segmentation clock and the Hox clock accounts for the diversity of vertebral formulae across animal species.
2012-05-23 | GSE38107 | GEO
Project description:The segmental organization of the vertebral column is established early in embryogenesis when pairs of somites are rhythmically produced by the presomitic mesoderm (PSM). The tempo of somite formation is controlled by a molecular oscillator known as the segmentation clock. While this oscillator has been well-characterized in model organisms, whether a similar oscillator exists in humans remains unknown. Genetic analysis of patients with severe spine segmentation defects have implicated several human orthologs of cyclic genes associated with the mouse segmentation clock, suggesting that this oscillator might be conserved in humans. Here we show that in vitro-derived human as well as mouse PSM cells recapitulate oscillations of the segmentation clock. Human PSM cells oscillate twice slower than mouse cells (5-hours vs. 2.5 hours), but are similarly regulated by FGF, Wnt, Notch and YAP. Single cell RNA-sequencing reveals that mouse and human PSM cells in vitro follow a similar developmental trajectory to mouse PSM in vivo. Furthermore, we demonstrate that FGF signaling controls the phase and period of oscillations, expanding the role of this pathway beyond its classical interpretation in 'Clock and Wavefront' models. Overall, our work identifying the human segmentation clock represents an important breakthrough for human developmental biology.
2019-10-28 | GSE114186 | GEO
Project description:Within a given vertebrate species, the total number of vertebrae in each anatomical domain is precisely defined and shows little variation among individuals. In contrast, this number can vary tremendously between different species, ranging from as few as six vertebrae in frogs to as many as several hundred in some snakes and fish. Segmental precursors of the vertebrae, called somites are produced sequentially in the embryo from the presomitic mesoderm (PSM), until a final number characteristic of the species, is reached. Here, we show in the chicken embryo that, by controlling the rate of axis elongation, Hox genes control the total number of somites generated by the embryo. We observed that activation of the most posterior Hox genes in somite precursors of the tail bud correlates with an abrupt slowing-down of the speed of axis elongation. We show that progressively more posterior Hox genes, which are collinearly activated in somitic precursors of the epiblast, repress Wnt activity with increasing strength. This leads to a graded repression of the Brachyury/T transcription factor, reducing mesoderm ingression and slowing down the elongation process. Due to the continuation of somite formation, the PSM, which is not fed with sufficient supply of new cells posteriorly, becomes progressively exhausted, ultimately leading to an arrest of segment formation. Our data provide a conceptual framework to explain how the cross-talk between the segmentation clock and the Hox clock accounts for the diversity of vertebral formulae across animal species. Primitive streak aera corresponding to PSM precursors were dissected in Stage 9 somites chicken embryo overexpressing HoxA13 or a control H2B-Venus. The experiment was designed to have biological duplicate in each conditions. The gain-of-function was obtained by electroporating the embryo at Stage 5HH with a vector containing HoxA13 under the CAGGS promoter with an H2B venus reporter. In order to have enough material for the microarray, 7 embryos were pooled in each sample before the hybridization.
2012-05-22 | E-GEOD-38107 | biostudies-arrayexpress
Project description:Pluripotent stem cells (PSCs) have increasingly been used to model different aspects of embryogenesis and organ formation. Despite recent advances in the in vitro induction of major mesodermal lineages and mesoderm-derived cell types experimental model systems that can recapitulate more complex biological features of human mesoderm development and patterning are largely missing. Here, we utilized induced pluripotent stem cells (iPSCs) for the stepwise in vitro induction of presomitic mesoderm (PSM) and its derivatives to model distinct aspects of human somitogenesis. We focused initially on modeling the human segmentation clock, a major biological concept believed to underlie the rhythmic and controlled emergence of somites, which give rise to the segmental pattern of the vertebrate axial skeleton. We succeeded to observe oscillatory expression of core segmentation clock genes, including HES7 and DKK1, determined the period of the human segmentation clock to be around five hours and showed the presence of dynamic traveling wave-like gene expression within in vitro induced human PSM. We furthermore identified and compared oscillatory genes in human and murine PSC-derived PSM, which revealed species-specific as well as common molecular components and novel pathways associated with the mouse and human segmentation clocks. Utilizing CRISPR/Cas9-based genome editing technology, we then targeted genes, for which mutations in patients with segmentation defects of vertebrae (SDV) such as spondylocostal dysostosis (SCD) have been reported (e.g. HES7, LFNG, DLL3 and MESP2 DLL3). Subsequent analysis of patient-like knock-out and point-mutation lines as well as patient-derived iPSCs together with their genetically corrected isogenic controls revealed gene-specific alterations in oscillation, synchronization or differentiation properties, validating the overall utility of our model system, to provide novel insights into the human segmentation clock as well as diseases associated with the formation of the human axial skeleton.
2020-01-13 | GSE116934 | GEO