scholarly journals Cell signalling stabilizes morphogenesis against noise

2019 ◽  
Author(s):  
Pascal Hagolani ◽  
Roland Zimm ◽  
Miquel Marin-Riera ◽  
Isaac Salazar-Ciudad
Keyword(s):  
Cell Division ◽  
Gene Networks ◽  
Cell Signalling ◽  
Huge Number ◽  
Cell Behaviors ◽  
Animal Development ◽  
Extracellular Signaling ◽  
General Mathematical Model ◽  
Robust To Noise ◽  
Early Metazoan

AbstractEmbryonic development involves gene networks, extracellular signaling, cell behaviors (cell division, apoptosis, adhesion, etc.) and mechanical interactions. How should gene networks, extracellular signaling and cell behaviors be coordinated to lead to complex and robust morphologies?To explore this question, we randomly wired genes and cell behaviors into a huge number of networks in EmbryoMaker. EmbryoMaker is a general mathematical model of animal development that simulates how embryos change,i.e.how the 3D spatial position of cells change, over time due such networks. Real gene networks are not random. Random networks, however, allow an unbiased view on the requirements for complex and robust development.We found that the mere autonomous activation of cell behaviors, especially cell division and contraction, was able to lead to the development of complex morphologies. We also found that complex morphologies tend to be less robust to noise than simple morphologies. However, we found that morphologies that developed through extracellular signaling and complex gene networks were, on average, more robust to noise. This stabilization occurs when gene networks and extracellular signaling partition the embryo into different regions where cell behaviors are regulated in slightly different ways. Our results are consistent with theories proposing that morphological complexity arose in early metazoan evolution as a consequence of the cell bio-mechanics already present in protozoa and that robustness evolved by the co-option of gene networks and extracellular cell signaling.

scholarly journals On the evolution and development of morphological complexity: A view from gene regulatory networks

2021 ◽  
Vol 17 (2) ◽  
pp. e1008570
Author(s):  
Pascal F. Hagolani ◽  
Roland Zimm ◽  
Renske Vroomans ◽  
Isaac Salazar-Ciudad
Keyword(s):  
Gene Networks ◽  
Animal Cell ◽  
Random Network ◽  
Random Search ◽  
Single Cells ◽  
Cell Behaviors ◽  
Morphological Complexity ◽  
Specific Distribution ◽  
Phenotypic Complexity ◽  
Robust To Noise

How does morphological complexity evolve? This study suggests that the likelihood of mutations increasing phenotypic complexity becomes smaller when the phenotype itself is complex. In addition, the complexity of the genotype-phenotype map (GPM) also increases with the phenotypic complexity. We show that complex GPMs and the above mutational asymmetry are inevitable consequences of how genes need to be wired in order to build complex and robust phenotypes during development.We randomly wired genes and cell behaviors into networks in EmbryoMaker. EmbryoMaker is a mathematical model of development that can simulate any gene network, all animal cell behaviors (division, adhesion, apoptosis, etc.), cell signaling, cell and tissues biophysics, and the regulation of those behaviors by gene products. Through EmbryoMaker we simulated how each random network regulates development and the resulting morphology (i.e. a specific distribution of cells and gene expression in 3D). This way we obtained a zoo of possible 3D morphologies. Real gene networks are not random, but a random search allows a relatively unbiased exploration of what is needed to develop complex robust morphologies. Compared to the networks leading to simple morphologies, the networks leading to complex morphologies have the following in common: 1) They are rarer; 2) They need to be finely tuned; 3) Mutations in them tend to decrease morphological complexity; 4) They are less robust to noise; and 5) They have more complex GPMs. These results imply that, when complexity evolves, it does so at a progressively decreasing rate over generations. This is because as morphological complexity increases, the likelihood of mutations increasing complexity decreases, morphologies become less robust to noise, and the GPM becomes more complex. We find some properties in common, but also some important differences, with non-developmental GPM models (e.g. RNA, protein and gene networks in single cells).

scholarly journals Deconstructing Gastrulation at the Single Cell Level

2021 ◽  
Author(s):  
Tomer Stern ◽  
Sebastian J Streichan ◽  
Stanislav Y Shvartsman ◽  
Eric F Wieschaus
Keyword(s):  
Large Scale ◽  
Drosophila Embryo ◽  
Cell Segmentation ◽  
Model Organisms ◽  
Specific Cell ◽  
Cell Behaviors ◽  
Animal Development ◽  
Wide Range ◽  
Cell Groups ◽  
Epithelial Sheets

Gastrulation movements in all animal embryos start with regulated deformations of patterned epithelial sheets. Current studies of gastrulation use a wide range of model organisms and emphasize either large-scale tissue processes or dynamics of individual cells and cell groups. Here we take a step towards bridging these complementary strategies and deconstruct early stages of gastrulation in the entire Drosophila embryo, where transcriptional patterns in the blastoderm give rise to region-specific cell behaviors. Our approach relies on an integrated computational framework for cell segmentation and tracking and on efficient algorithms for event detection. Our results reveal how thousands of cell shape changes, divisions, and intercalations drive large-scale deformations of the patterned blastoderm, setting the stage for systems-level dissection of a pivotal step in animal development.

scholarly journals Wnt-and Glutamate-receptors orchestrate stem cell dynamics and asymmetric cell division

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Sergi Junyent ◽  
Joshua C Reeves ◽  
James LA Szczerkowski1 ◽  
Clare L Garcin ◽  
Tung-Jui Trieu ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Division ◽  
Glutamate Receptors ◽  
Cell Fate ◽  
Cell Biology ◽  
Wnt Pathway ◽  
Asymmetric Cell Division ◽  
Cell Signalling ◽  
Embryonic Stem ◽  
Kainate Receptors

The Wnt-pathway is part of a signalling network that regulates many aspects of cell biology. Recently we discovered crosstalk between AMPA/Kainate-type ionotropic glutamate receptors (iGluRs) and the Wnt-pathway during the initial Wnt3a-interaction at the cytonemes of mouse embryonic stem cells (ESCs). Here, we demonstrate that this crosstalk persists throughout the Wnt3a-response in ESCs. Both AMPA- and Kainate-receptors regulate early Wnt3a-recruitment, dynamics on the cell membrane, and orientation of the spindle towards a Wnt3a-source at mitosis. AMPA-receptors specifically are required for segregating cell fate components during Wnt3a-mediated asymmetric cell division (ACD). Using Wnt-pathway component knockout lines, we determine that Wnt co-receptor Lrp6 has particular functionality over Lrp5 in cytoneme formation, and in facilitating ACD. Both Lrp5 and 6, alongside pathway effector β-catenin act in concert to mediate the positioning of the dynamic interaction with, and spindle orientation to, a localized Wnt3a-source. Wnt-iGluR crosstalk may prove pervasive throughout embryonic and adult stem cell signalling.

Initiation of the proximodistal axis in insect legs

Development ◽  
1995 ◽  
Vol 121 (3) ◽  
pp. 619-628 ◽  
Author(s):  
G. Campbell ◽  
A. Tomlinson
Keyword(s):  
Protein Expression ◽  
Close Association ◽  
Cell Communication ◽  
Signaling Molecules ◽  
Cell Fates ◽  
Animal Development ◽  
Extracellular Signaling ◽  
Cell Cell

Much of the cell-cell communication that controls assignment of cell fates during animal development appears to be mediated by extracellular signaling molecules. The formation of the proximodistal (P/D) axis of the legs of flies is controlled by at least two such molecules, a Wnt and a TGFbeta, encoded by the wingless (wg) and decapentaplegic (dpp) genes, respectively. The P/D axis appears to be initiated from the site where cells expressing wg are in close association with those expressing dpp. Support for this hypothesis comes from two sources: classical grafting experiments in cockroaches and ectopic protein expression in Drosophila.

scholarly journals Cell behaviors within a confined adhesive area fabricated using novel micropatterning methods

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262632
Author(s):  
Tsukasa Nakatoh ◽  
Takuji Osaki ◽  
Sohma Tanimoto ◽  
Md. Golam Sarowar Jahan ◽  
Tomohisa Kawakami ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Division ◽  
Single Cells ◽  
Cell Behavior ◽  
Air Plasma ◽  
Cell Behaviors ◽  
Laser Ablation Method ◽  
Increasing Demand ◽  
Division Cell ◽  
Adhesive Coating

In the field of cell and tissue engineering, there is an increasing demand for techniques to spatially control the adhesion of cells to substrates of desired sizes and shapes. Here, we describe two novel methods for fabricating a substrate for adhesion of cells to a defined area. In the first method, the surface of the coverslip or plastic dish was coated with Lipidure, a non-adhesive coating material, and air plasma was applied through a mask with holes, to confer adhesiveness to the surface. In the second method, after the surface of the coverslip was coated with gold by sputtering and then with Lipidure; the Lipidure coat was locally removed using a novel scanning laser ablation method. These methods efficiently confined cells within the adhesive area and enabled us to follow individual cells for a longer duration, compared to the currently available commercial substrates. By following single cells within the confined area, we were able to observe several new aspects of cell behavior in terms of cell division, cell–cell collisions, and cell collision with the boundary between adhesive and non-adhesive areas.

scholarly journals Uniaxial loading induces a scalable switch in cortical actomyosin flow polarization and reveals mechanosensitive regulation of cytokinesis

2019 ◽  
Author(s):  
Deepika Singh ◽  
Devang Odedra ◽  
Christian Pohl
Keyword(s):  
Cell Division ◽  
Stress Response ◽  
Mechanical Stress ◽  
Rotational Flow ◽  
Mechanical Forces ◽  
Longitudinal Flow ◽  
Contractile Ring ◽  
Animal Development ◽  
C Elegans ◽  
Cortical Fibers

AbstractDuring animal development, it is crucial that cells can sense and adapt to mechanical forces from their environment. Ultimately, these forces are transduced through the actomyosin cortex. How the cortex can simultaneously respond to and create forces during cytokinesis is not well understood. Here we show that under mechanical stress, cortical actomyosin flow switches its polarization during cytokinesis in the C. elegans embryo. In unstressed embryos, longitudinal cortical flows contribute to contractile ring formation, while rotational cortical flow is additionally induced in uniaxially loaded embryos. Rotational cortical flow is required for the redistribution of the actomyosin cortex in loaded embryos. Rupture of longitudinally aligned cortical fibers during cortex rotation releases tension, initiates orthogonal longitudinal flow and thereby contributes to furrowing in loaded embryos. A targeted screen for factors required for rotational flow revealed that actomyosin regulators involved in RhoA regulation, cortical polarity and chirality are all required for rotational flow and become essential for cytokinesis under mechanical stress. In sum, our findings extend the current framework of mechanical stress response during cell division and show scaling of orthogonal cortical flows to the amount of mechanical stress.

scholarly journals Editorial

2018 ◽  
Vol 29 (6) ◽  
pp. 969-971
Author(s):  
Hermann Eberl ◽  
John Ward
Keyword(s):  
Cell Division ◽  
Quorum Sensing ◽  
Nutrient Concentration ◽  
Extracellular Polymeric Substances ◽  
Cell Signalling ◽  
Single Species ◽  
Bacterial Biofilms ◽  
Liquid Interfaces ◽  
Solid Liquid ◽  
Biofilm Matrix

Biofilms are colonies of microorganisms, usually growing on solid-liquid interfaces, consisting of cells and a matrix of extracellular polymeric substances (EPS). Such colonies are often elaborately structured and highly dynamic, expanding through cell division and recruitment of cells from outside, and contracting via individual cells or flocs (groups of cells and biofilm matrix) detachment from the biofilm surface. Even amongst simplest single species bacterial biofilms, the behaviour (phenotype) of individual cells is highly heterogenous across the biofilm due to microenvironment variation (e.g. nutrient concentration, pH) and cell-cell signalling (quorum sensing); consequently, many researchers consider biofilms as more akin to multi-cellular organisms rather than a colony of autonomous individual cells.

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