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Cells May 2023Elongation of the posterior body axis is distinct from that of the anterior trunk and head. Early drivers of posterior elongation are the neural plate/tube and...
Elongation of the posterior body axis is distinct from that of the anterior trunk and head. Early drivers of posterior elongation are the neural plate/tube and notochord, later followed by the presomitic mesoderm (PSM), together with the neural tube and notochord. In axolotl, posterior neural plate-derived PSM is pushed posteriorly by convergence and extension of the neural plate. The PSM does not go through the blastopore but turns anteriorly to join the gastrulated paraxial mesoderm. To gain a deeper understanding of the process of axial elongation, a detailed characterization of PSM morphogenesis, which precedes somite formation, and of other tissues (such as the epidermis, lateral plate mesoderm and endoderm) is needed. We investigated these issues with specific tissue labelling techniques (DiI injections and GFP tissue grafting) in combination with optical tissue clearing and 3D reconstructions. We defined a spatiotemporal order of PSM morphogenesis that is characterized by changes in collective cell behaviour. The PSM forms a cohesive tissue strand and largely retains this cohesiveness even after epidermis removal. We show that during embryogenesis, the PSM, as well as the lateral plate and endoderm move anteriorly, while the net movement of the axis is posterior.
Topics: Neural Plate; Mesoderm; Morphogenesis; Embryonic Development; Muscles
PubMed: 37174713
DOI: 10.3390/cells12091313 -
Zoological Research May 2023The biological function of the novel zinc-finger SWIM domain-containing protein family (ZSWIM) during embryonic development remains elusive. Here, we conducted a...
The biological function of the novel zinc-finger SWIM domain-containing protein family (ZSWIM) during embryonic development remains elusive. Here, we conducted a genome-wide analysis to explore the evolutionary processes of the gene family members in mice, , zebrafish, and humans. We identified nine putative genes in the human and mouse genome, eight in the genome, and five in the zebrafish genome. Based on multiple sequence alignment, three members, ZSWIM5, ZSWIM6, and ZSWIM8, demonstrated the highest homology across all four species. Using available RNA sequencing (RNA-seq) data, genes were found to be widely expressed across different tissues, with distinct tissue-specific properties. To identify the functions of the ZSWIM protein family during embryogenesis, we examined temporal and spatial expression patterns of family genes in embryos Quantitative real-time polymerase chain reaction (qRT-PCR) revealed that each member had a distinct expression profile. Whole-mount hybridization showed that both and were maternally expressed genes; and were expressed throughout embryogenesis and displayed dynamic expression in the brain, eyes, somite, and bronchial arch at the late tailbud stages; was detected in the eye area; showed a dynamic expression pattern during the tailbud stages, with expression detected in the brain, eyes, and somite; was faintly expressed throughout embryonic development. This study provides a foundation for future research to delineate the functions of gene members.
Topics: Female; Pregnancy; Humans; Animals; Mice; Zebrafish; Xenopus; Biological Evolution; Brain; Zinc Fingers; DNA-Binding Proteins
PubMed: 37161653
DOI: 10.24272/j.issn.2095-8137.2022.418 -
Developmental Cell Jun 2023Oscillator systems achieve synchronization when oscillators are coupled. The presomitic mesoderm is a system of cellular oscillators, where coordinated genetic activity...
Oscillator systems achieve synchronization when oscillators are coupled. The presomitic mesoderm is a system of cellular oscillators, where coordinated genetic activity is necessary for proper periodic generation of somites. While Notch signaling is required for the synchronization of these cells, it is unclear what information the cells exchange and how they react to this information to align their oscillatory pace with that of their neighbors. Combining mathematical modeling and experimental data, we found that interaction between murine presomitic mesoderm cells is controlled by a phase-gated and unidirectional coupling mechanism and results in deceleration of their oscillation pace upon Notch signaling. This mechanism predicts that isolated populations of well-mixed cells synchronize, revealing a stereotypical synchronization in the mouse PSM and contradicting expectations from previously applied theoretical approaches. Collectively, our theoretical and experimental findings reveal the underlying coupling mechanisms of the presomitic mesoderm cells and provide a framework to quantitatively characterize their synchronization.
Topics: Mice; Animals; Biological Clocks; Somites; Mesoderm; Models, Theoretical; Signal Transduction; Gene Expression Regulation, Developmental; Receptors, Notch
PubMed: 37098349
DOI: 10.1016/j.devcel.2023.04.002 -
Frontiers in Cell and Developmental... 2023Pattern formation is the process by which cells within a homogeneous epithelial sheet acquire distinctive fates depending upon their relative spatial position to each... (Review)
Review
Pattern formation is the process by which cells within a homogeneous epithelial sheet acquire distinctive fates depending upon their relative spatial position to each other. Several proposals, starting with Alan Turing's diffusion-reaction model, have been put forth over the last 70 years to describe how periodic patterns like those of vertebrate somites and skin hairs, mammalian molars, fish scales, and avian feather buds emerge during development. One of the best experimental systems for testing said models and identifying the gene regulatory networks that control pattern formation is the compound eye of the fruit fly, . Its cellular morphogenesis has been extensively studied for more than a century and hundreds of mutants that affect its development have been isolated. In this review we will focus on the morphogenetic furrow, a wave of differentiation that takes an initially homogeneous sheet of cells and converts it into an ordered array of unit eyes or ommatidia. Since the discovery of the furrow in 1976, positive and negative acting morphogens have been thought to be solely responsible for propagating the movement of the furrow across a motionless field of cells. However, a recent study has challenged this model and instead proposed that mechanical driven cell flow also contributes to retinal pattern formation. We will discuss both models and their impact on patterning.
PubMed: 37091979
DOI: 10.3389/fcell.2023.1151348 -
BioRxiv : the Preprint Server For... Jun 2023During vertebrate embryogenesis, axial tendons develop from the paraxial mesoderm and differentiate through specific developmental stages to reach the syndetome stage....
During vertebrate embryogenesis, axial tendons develop from the paraxial mesoderm and differentiate through specific developmental stages to reach the syndetome stage. While the main roles of signaling pathways in the earlier stages of the differentiation have been well established, pathway nuances in syndetome specification from the sclerotome stage have yet to be explored. Here, we show stepwise differentiation of human iPSCs to the syndetome stage using chemically defined media and small molecules that were modified based on single cell RNA-sequencing and pathway analysis. We identified a significant population of branching off-target cells differentiating towards a neural phenotype overexpressing Wnt. Further transcriptomics post-addition of a WNT inhibitor at the somite stage and onwards revealed not only total removal of the neural off-target cells, but also increased syndetome induction efficiency. Fine-tuning tendon differentiation is essential to address the current challenges in developing a successful cell-based tendon therapy.
PubMed: 37090543
DOI: 10.1101/2023.04.10.536240 -
Cell Reports Apr 2023Recent advances in synthetic embryology have opened new avenues for understanding the complex events controlling mammalian peri-implantation development. Here, we show...
Recent advances in synthetic embryology have opened new avenues for understanding the complex events controlling mammalian peri-implantation development. Here, we show that mouse embryonic stem cells (ESCs) solely exposed to chemical inhibition of SUMOylation generate embryo-like structures comprising anterior neural and trunk-associated regions. HypoSUMOylation-instructed ESCs give rise to spheroids that self-organize into gastrulating structures containing cell types spatially and functionally related to embryonic and extraembryonic compartments. Alternatively, spheroids cultured in a droplet microfluidic device form elongated structures that undergo axial organization reminiscent of natural embryo morphogenesis. Single-cell transcriptomics reveals various cellular lineages, including properly positioned anterior neuronal cell types and paraxial mesoderm segmented into somite-like structures. Transient SUMOylation suppression gradually increases DNA methylation genome wide and repressive mark deposition at Nanog. Interestingly, cell-to-cell variations in SUMOylation levels occur during early embryogenesis. Our approach provides a proof of principle for potentially powerful strategies to explore early embryogenesis by targeting chromatin roadblocks of cell fate change.
Topics: Animals; Mice; Sumoylation; Embryo, Mammalian; Embryonic Stem Cells; Embryonic Development; Cell Differentiation; Mammals
PubMed: 37061916
DOI: 10.1016/j.celrep.2023.112380 -
Nature Communications Apr 2023The metameric pattern of somites is created based on oscillatory expression of clock genes in presomitic mesoderm. However, the mechanism for converting the dynamic...
The metameric pattern of somites is created based on oscillatory expression of clock genes in presomitic mesoderm. However, the mechanism for converting the dynamic oscillation to a static pattern of somites is still unclear. Here, we provide evidence that Ripply/Tbx6 machinery is a key regulator of this conversion. Ripply1/Ripply2-mediated removal of Tbx6 protein defines somite boundary and also leads to cessation of clock gene expression in zebrafish embryos. On the other hand, activation of ripply1/ripply2 mRNA and protein expression is periodically regulated by clock oscillation in conjunction with an Erk signaling gradient. Whereas Ripply protein decreases rapidly in embryos, Ripply-triggered Tbx6 suppression persists long enough to complete somite boundary formation. Mathematical modeling shows that a molecular network based on results of this study can reproduce dynamic-to-static conversion in somitogenesis. Furthermore, simulations with this model suggest that sustained suppression of Tbx6 caused by Ripply is crucial in this conversion.
Topics: Animals; Somites; Zebrafish; T-Box Domain Proteins; Mesoderm; Zebrafish Proteins; Gene Expression Regulation, Developmental
PubMed: 37055428
DOI: 10.1038/s41467-023-37745-w -
PloS One 2023SLC35A3 is considered an uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) transporter in mammals and regulates the branching of N-glycans. A missense mutation in...
SLC35A3 is considered an uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) transporter in mammals and regulates the branching of N-glycans. A missense mutation in SLC35A3 causes complex vertebral malformation (CVM) in cattle. However, the biological functions of SLC35A3 have not been fully clarified. To address these issues, we have established Slc35a3-/-mice using CRISPR/Cas9 genome editing system. The generated mutant mice were perinatal lethal and exhibited chondrodysplasia recapitulating CVM-like vertebral anomalies. During embryogenesis, Slc35a3 mRNA was expressed in the presomitic mesoderm of wild-type mice, suggesting that SLC35A3 transports UDP-GlcNAc used for the sugar modification that is essential for somite formation. In the growth plate cartilage of Slc35a3-/-embryos, extracellular space was drastically reduced, and many flat proliferative chondrocytes were reshaped. Proliferation, apoptosis and differentiation were not affected in the chondrocytes of Slc35a3-/-mice, suggesting that the chondrodysplasia phenotypes were mainly caused by the abnormal extracellular matrix quality. Because these histological abnormalities were similar to those observed in several mutant mice accompanying the impaired glycosaminoglycan (GAG) biosynthesis, GAG levels were measured in the spine and limbs of Slc35a3-/-mice using disaccharide composition analysis. Compared with control mice, the amounts of heparan sulfate, keratan sulfate, and chondroitin sulfate/dermatan sulfate, were significantly decreased in Slc35a3-/-mice. These findings suggest that SLC35A3 regulates GAG biosynthesis and the chondrodysplasia phenotypes were partially caused by the decreased GAG synthesis. Hence, Slc35a3-/- mice would be a useful model for investigating the in vivo roles of SLC35A3 and the pathological mechanisms of SLC35A3-associated diseases.
Topics: Animals; Cattle; Mice; Biological Transport; Keratan Sulfate; Mammals; Musculoskeletal Abnormalities; Nucleotides; Osteochondrodysplasias; Uridine Diphosphate
PubMed: 37053259
DOI: 10.1371/journal.pone.0284292 -
Cardiovascular Research Jul 2023Congenital heart disease (CHD) is the most common genetic birth defect, which has considerable morbidity and mortality. We focused on deciphering key regulators that...
AIMS
Congenital heart disease (CHD) is the most common genetic birth defect, which has considerable morbidity and mortality. We focused on deciphering key regulators that govern cardiac progenitors and cardiogenesis. FOXK1 is a forkhead/winged helix transcription factor known to regulate cell cycle kinetics and is restricted to mesodermal progenitors, somites, and heart. In the present study, we define an essential role for FOXK1 during cardiovascular development.
METHODS AND RESULTS
We used the mouse embryoid body system to differentiate control and Foxk1 KO embryonic stem cells into mesodermal, cardiac progenitor cells and mature cardiac cells. Using flow cytometry, immunohistochemistry, cardiac beating, transcriptional and chromatin immunoprecipitation quantitative polymerase chain reaction assays, bulk RNA sequencing (RNAseq) and assay for transposase-accessible chromatin using sequencing (ATACseq) analyses, FOXK1 was observed to be an important regulator of cardiogenesis. Flow cytometry analyses revealed perturbed cardiogenesis in Foxk1 KO embryoid bodies (EBs). Bulk RNAseq analysis at two developmental stages showed a significant reduction of the cardiac molecular program in Foxk1 KO EBs compared to the control EBs. ATACseq analysis during EB differentiation demonstrated that the chromatin landscape nearby known important regulators of cardiogenesis was significantly relaxed in control EBs compared to Foxk1 KO EBs. Furthermore, we demonstrated that in the absence of FOXK1, cardiac differentiation was markedly impaired by assaying for cardiac Troponin T expression and cardiac contractility. We demonstrate that FOXK1 is an important regulator of cardiogenesis by repressing the Wnt/β-catenin signalling pathway and thereby promoting differentiation.
CONCLUSION
These results identify FOXK1 as an essential transcriptional and epigenetic regulator of cardiovascular development. Mechanistically, FOXK1 represses Wnt signalling to promote the development of cardiac progenitor cells.
Topics: Animals; Mice; Cell Differentiation; Embryonic Stem Cells; Heart; Wnt Signaling Pathway
PubMed: 37036809
DOI: 10.1093/cvr/cvad054 -
BioRxiv : the Preprint Server For... Mar 2023In bony fishes, formation of the vertebral column, or spine, is guided by a metameric blueprint established in the epithelial sheath of the notochord. Generation of the...
In bony fishes, formation of the vertebral column, or spine, is guided by a metameric blueprint established in the epithelial sheath of the notochord. Generation of the notochord template begins days after somitogenesis and even occurs in the absence of somite segmentation. However, patterning defects in the somites lead to imprecise notochord segmentation, suggesting these processes are linked. Here, we reveal that spatial coordination between the notochord and the axial musculature is necessary to ensure segmentation of the zebrafish spine both in time and space. We find that the connective tissues that anchor the axial skeletal musculature, known as the myosepta in zebrafish, transmit spatial patterning cues necessary to initiate notochord segment formation, a critical pre-patterning step in spine morphogenesis. When an irregular pattern of muscle segments and myosepta interact with the notochord sheath, segments form non-sequentially, initiate at atypical locations, and eventually display altered morphology later in development. We determine that locations of myoseptum-notochord connections are hubs for mechanical signal transmission, which are characterized by localized sites of deformation of the extracellular matrix (ECM) layer encasing the notochord. The notochord sheath responds to the external mechanical changes by locally augmenting focal adhesion machinery to define the initiation site for segmentation. Using a coarse-grained mathematical model that captures the spatial patterns of myoseptum-notochord interactions, we find that a fixed-length scale of external cues is critical for driving sequential segment patterning in the notochord. Together, this work identifies a robust segmentation mechanism that hinges upon mechanical coupling of adjacent tissues to control patterning dynamics.
PubMed: 37034817
DOI: 10.1101/2023.03.27.534101