--- _id: '1406' abstract: - lang: eng text: Epithelial spreading is a critical part of various developmental and wound repair processes. Here we use zebrafish epiboly as a model system to study the cellular and molecular mechanisms underlying the spreading of epithelial sheets. During zebrafish epiboly the enveloping cell layer (EVL), a simple squamous epithelium, spreads over the embryo to eventually cover the entire yolk cell by the end of gastrulation. The EVL leading edge is anchored through tight junctions to the yolk syncytial layer (YSL), where directly adjacent to the EVL margin a contractile actomyosin ring is formed that is thought to drive EVL epiboly. The prevalent view in the field was that the contractile ring exerts a pulling force on the EVL margin, which pulls the EVL towards the vegetal pole. However, how this force is generated and how it affects EVL morphology still remains elusive. Moreover, the cellular mechanisms mediating the increase in EVL surface area, while maintaining tissue integrity and function are still unclear. Here we show that the YSL actomyosin ring pulls on the EVL margin by two distinct force-generating mechanisms. One mechanism is based on contraction of the ring around its circumference, as previously proposed. The second mechanism is based on actomyosin retrogade flows, generating force through resistance against the substrate. The latter can function at any epiboly stage even in situations where the contraction-based mechanism is unproductive. Additionally, we demonstrate that during epiboly the EVL is subjected to anisotropic tension, which guides the orientation of EVL cell division along the main axis (animal-vegetal) of tension. The influence of tension in cell division orientation involves cell elongation and requires myosin-2 activity for proper spindle alignment. Strikingly, we reveal that tension-oriented cell divisions release anisotropic tension within the EVL and that in the absence of such divisions, EVL cells undergo ectopic fusions. We conclude that forces applied to the EVL by the action of the YSL actomyosin ring generate a tension anisotropy in the EVL that orients cell divisions, which in turn limit tissue tension increase thereby facilitating tissue spreading. acknowledged_ssus: - _id: Bio - _id: PreCl alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Pedro full_name: Campinho, Pedro id: 3AFBBC42-F248-11E8-B48F-1D18A9856A87 last_name: Campinho orcid: 0000-0002-8526-5416 citation: ama: 'Campinho P. Mechanics of zebrafish epiboly: Tension-oriented cell divisions limit anisotropic tissue tension in epithelial spreading. 2013.' apa: 'Campinho, P. (2013). Mechanics of zebrafish epiboly: Tension-oriented cell divisions limit anisotropic tissue tension in epithelial spreading. Institute of Science and Technology Austria.' chicago: 'Campinho, Pedro. “Mechanics of Zebrafish Epiboly: Tension-Oriented Cell Divisions Limit Anisotropic Tissue Tension in Epithelial Spreading.” Institute of Science and Technology Austria, 2013.' ieee: 'P. Campinho, “Mechanics of zebrafish epiboly: Tension-oriented cell divisions limit anisotropic tissue tension in epithelial spreading,” Institute of Science and Technology Austria, 2013.' ista: 'Campinho P. 2013. Mechanics of zebrafish epiboly: Tension-oriented cell divisions limit anisotropic tissue tension in epithelial spreading. Institute of Science and Technology Austria.' mla: 'Campinho, Pedro. Mechanics of Zebrafish Epiboly: Tension-Oriented Cell Divisions Limit Anisotropic Tissue Tension in Epithelial Spreading. Institute of Science and Technology Austria, 2013.' short: 'P. Campinho, Mechanics of Zebrafish Epiboly: Tension-Oriented Cell Divisions Limit Anisotropic Tissue Tension in Epithelial Spreading, Institute of Science and Technology Austria, 2013.' date_created: 2018-12-11T11:51:50Z date_published: 2013-10-01T00:00:00Z date_updated: 2023-09-07T11:36:07Z day: '01' degree_awarded: PhD department: - _id: CaHe language: - iso: eng month: '10' oa_version: None page: '123' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria publist_id: '5801' status: public supervisor: - first_name: Carl-Philipp J full_name: Heisenberg, Carl-Philipp J id: 39427864-F248-11E8-B48F-1D18A9856A87 last_name: Heisenberg orcid: 0000-0002-0912-4566 title: 'Mechanics of zebrafish epiboly: Tension-oriented cell divisions limit anisotropic tissue tension in epithelial spreading' type: dissertation user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2013' ... --- _id: '3396' abstract: - lang: eng text: Facial branchiomotor neurons (FBMNs) in zebrafish and mouse embryonic hindbrain undergo a characteristic tangential migration from rhombomere (r) 4, where they are born, to r6/7. Cohesion among neuroepithelial cells (NCs) has been suggested to function in FBMN migration by inhibiting FBMNs positioned in the basal neuroepithelium such that they move apically between NCs towards the midline of the neuroepithelium instead of tangentially along the basal side of the neuroepithelium towards r6/7. However, direct experimental evaluation of this hypothesis is still lacking. Here, we have used a combination of biophysical cell adhesion measurements and high-resolution time-lapse microscopy to determine the role of NC cohesion in FBMN migration. We show that reducing NC cohesion by interfering with Cadherin 2 (Cdh2) activity results in FBMNs positioned at the basal side of the neuroepithelium moving apically towards the neural tube midline instead of tangentially towards r6/7. In embryos with strongly reduced NC cohesion, ectopic apical FBMN movement frequently results in fusion of the bilateral FBMN clusters over the apical midline of the neural tube. By contrast, reducing cohesion among FBMNs by interfering with Contactin 2 (Cntn2) expression in these cells has little effect on apical FBMN movement, but reduces the fusion of the bilateral FBMN clusters in embryos with strongly diminished NC cohesion. These data provide direct experimental evidence that NC cohesion functions in tangential FBMN migration by restricting their apical movement. acknowledged_ssus: - _id: Bio - _id: PreCl article_type: original author: - first_name: Petra full_name: Stockinger, Petra id: 261CB030-E90D-11E9-B182-F697D44B663C last_name: Stockinger - first_name: Carl-Philipp J full_name: Heisenberg, Carl-Philipp J id: 39427864-F248-11E8-B48F-1D18A9856A87 last_name: Heisenberg orcid: 0000-0002-0912-4566 - first_name: Jean-Léon full_name: Maître, Jean-Léon id: 48F1E0D8-F248-11E8-B48F-1D18A9856A87 last_name: Maître orcid: 0000-0002-3688-1474 citation: ama: Stockinger P, Heisenberg C-PJ, Maître J-L. Defective neuroepithelial cell cohesion affects tangential branchiomotor neuron migration in the zebrafish neural tube. Development. 2011;138(21):4673-4683. doi:10.1242/dev.071233 apa: Stockinger, P., Heisenberg, C.-P. J., & Maître, J.-L. (2011). Defective neuroepithelial cell cohesion affects tangential branchiomotor neuron migration in the zebrafish neural tube. Development. Company of Biologists. https://doi.org/10.1242/dev.071233 chicago: Stockinger, Petra, Carl-Philipp J Heisenberg, and Jean-Léon Maître. “Defective Neuroepithelial Cell Cohesion Affects Tangential Branchiomotor Neuron Migration in the Zebrafish Neural Tube.” Development. Company of Biologists, 2011. https://doi.org/10.1242/dev.071233. ieee: P. Stockinger, C.-P. J. Heisenberg, and J.-L. Maître, “Defective neuroepithelial cell cohesion affects tangential branchiomotor neuron migration in the zebrafish neural tube,” Development, vol. 138, no. 21. Company of Biologists, pp. 4673–4683, 2011. ista: Stockinger P, Heisenberg C-PJ, Maître J-L. 2011. Defective neuroepithelial cell cohesion affects tangential branchiomotor neuron migration in the zebrafish neural tube. Development. 138(21), 4673–4683. mla: Stockinger, Petra, et al. “Defective Neuroepithelial Cell Cohesion Affects Tangential Branchiomotor Neuron Migration in the Zebrafish Neural Tube.” Development, vol. 138, no. 21, Company of Biologists, 2011, pp. 4673–83, doi:10.1242/dev.071233. short: P. Stockinger, C.-P.J. Heisenberg, J.-L. Maître, Development 138 (2011) 4673–4683. date_created: 2018-12-11T12:03:06Z date_published: 2011-09-28T00:00:00Z date_updated: 2021-01-12T07:43:11Z day: '28' ddc: - '570' department: - _id: CaHe doi: 10.1242/dev.071233 file: - access_level: open_access checksum: ca12b79e01ef36c1ef1aea31cf7e7139 content_type: application/pdf creator: dernst date_created: 2019-10-07T14:19:42Z date_updated: 2020-07-14T12:46:12Z file_id: '6930' file_name: 2011_Development_Stockinger.pdf file_size: 4672439 relation: main_file file_date_updated: 2020-07-14T12:46:12Z has_accepted_license: '1' intvolume: ' 138' issue: '21' language: - iso: eng month: '09' oa: 1 oa_version: Published Version page: 4673 - 4683 publication: Development publication_status: published publisher: Company of Biologists publist_id: '3210' quality_controlled: '1' scopus_import: 1 status: public title: Defective neuroepithelial cell cohesion affects tangential branchiomotor neuron migration in the zebrafish neural tube type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 138 year: '2011' ... --- _id: '4157' abstract: - lang: eng text: Integrin- and cadherin-mediated adhesion is central for cell and tissue morphogenesis, allowing cells and tissues to change shape without loosing integrity. Studies predominantly in cell culture showed that mechanosensation through adhesion structures is achieved by force-mediated modulation of their molecular composition. The specific molecular composition of adhesion sites in turn determines their signalling activity and dynamic reorganization. Here, we will review how adhesion sites respond to mecanical stimuli, and how spatially and temporally regulated signalling from different adhesion sites controls cell migration and tissue morphogenesis. acknowledged_ssus: - _id: Bio author: - first_name: Ekaterina full_name: Papusheva, Ekaterina id: 41DB591E-F248-11E8-B48F-1D18A9856A87 last_name: Papusheva - first_name: Carl-Philipp J full_name: Heisenberg, Carl-Philipp J id: 39427864-F248-11E8-B48F-1D18A9856A87 last_name: Heisenberg orcid: 0000-0002-0912-4566 citation: ama: 'Papusheva E, Heisenberg C-PJ. Spatial organization of adhesion: force-dependent regulation and function in tissue morphogenesis. EMBO Journal. 2010;29(16):2753-2768. doi:10.1038/emboj.2010.182' apa: 'Papusheva, E., & Heisenberg, C.-P. J. (2010). Spatial organization of adhesion: force-dependent regulation and function in tissue morphogenesis. EMBO Journal. Wiley-Blackwell. https://doi.org/10.1038/emboj.2010.182' chicago: 'Papusheva, Ekaterina, and Carl-Philipp J Heisenberg. “Spatial Organization of Adhesion: Force-Dependent Regulation and Function in Tissue Morphogenesis.” EMBO Journal. Wiley-Blackwell, 2010. https://doi.org/10.1038/emboj.2010.182.' ieee: 'E. Papusheva and C.-P. J. Heisenberg, “Spatial organization of adhesion: force-dependent regulation and function in tissue morphogenesis,” EMBO Journal, vol. 29, no. 16. Wiley-Blackwell, pp. 2753–2768, 2010.' ista: 'Papusheva E, Heisenberg C-PJ. 2010. Spatial organization of adhesion: force-dependent regulation and function in tissue morphogenesis. EMBO Journal. 29(16), 2753–2768.' mla: 'Papusheva, Ekaterina, and Carl-Philipp J. Heisenberg. “Spatial Organization of Adhesion: Force-Dependent Regulation and Function in Tissue Morphogenesis.” EMBO Journal, vol. 29, no. 16, Wiley-Blackwell, 2010, pp. 2753–68, doi:10.1038/emboj.2010.182.' short: E. Papusheva, C.-P.J. Heisenberg, EMBO Journal 29 (2010) 2753–2768. date_created: 2018-12-11T12:07:17Z date_published: 2010-08-18T00:00:00Z date_updated: 2021-01-12T07:54:55Z day: '18' department: - _id: Bio - _id: CaHe doi: 10.1038/emboj.2010.182 external_id: pmid: - '20717145' intvolume: ' 29' issue: '16' language: - iso: eng main_file_link: - open_access: '1' url: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2924654/ month: '08' oa: 1 oa_version: Submitted Version page: 2753 - 2768 pmid: 1 publication: EMBO Journal publication_status: published publisher: Wiley-Blackwell publist_id: '1962' quality_controlled: '1' scopus_import: 1 status: public title: 'Spatial organization of adhesion: force-dependent regulation and function in tissue morphogenesis' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 29 year: '2010' ...