Mechanical Induction in Embryonic Development and Tumor Growth: Integrative Cues Through Molecular to Multicellular Interplay and Evolutionary Perspectives

International audienceEmbryonic development is a coordination of multicellular biochemical patterning and morphogenetic movements. Last decades revealed the close control of myosin-II-dependent biomechanical morphogenesis by patterning gene expression, with constant progress in the understanding of the underlying molecular mechanisms. Reversed control of developmental gene expression and of myosin-II patterning by the mechanical strains developed by morphogenetic movements was recently revealed at Drosophila gastrulation, through mechanotransduction processes involving the Armadillo/beta-catenin and the downstream of Fog Rho pathways. Here, we present the theoretical (simulations integrating the accumulated knowledge in the genetics of early embryonic development and morphogenesis) and the experimental (genetic and biophysical control of morphogenetic movements) tools having allowed the uncoupling of pure genetic inputs from pure mechanical inputs in the regulation of gene expression and myosin-II patterning. Specifically, we describe the innovative magnetic tweezers tools we have set up to measure and apply physiological strains and forces in vivo, from the inside of the tissue, to modulate and mimic morphogenetic movements in living embryos. We discuss mechanical induction incidence in tumor development and perspective in evolution

Embryos Drosophila Invagination in Mechanical Signals Trigger Myosin II Redistribution and Mesoderm

International audienceThe following resources related to this article are available online at http://stke.sciencemag.org. Article Tools http://stke.sciencemag.org/cgi/content/full/sigtrans;2/66/ra16 Visit the online version of this article to access the personalization and article tools: Materials Supplemental http://stke.sciencemag.org/cgi/content/full/sigtrans;2/66/ra16/DC1 "Supplementary Materials" Related Content http://stke.sciencemag.org/cgi/content/abstract/sigtrans;2/66/eg4 's sites: Science The editors suggest related resources on References http://stke.sciencemag.org/cgi/content/full/sigtrans;2/66/ra16#otherarticles This article cites 34 articles, 13 of which can be accessed for free: Glossary http://stke.sciencemag.org/glossary/ Look up definitions for abbreviations and terms found in this article: Permissions http://www.sciencemag.org/about/permissions.dt

Evolutionary conservation of early mesoderm specification by mechanotransduction in Bilateria.

International audienceThe modulation of developmental biochemical pathways by mechanical cues is an emerging feature of animal development, but its evolutionary origins have not been explored. Here we show that a common mechanosensitive pathway involving β-catenin specifies early mesodermal identity at gastrulation in zebrafish and Drosophila. Mechanical strains developed by zebrafish epiboly and Drosophila mesoderm invagination trigger the phosphorylation of β-catenin-tyrosine-667. This leads to the release of β-catenin into the cytoplasm and nucleus, where it triggers and maintains, respectively, the expression of zebrafish brachyury orthologue notail and of Drosophila Twist, both crucial transcription factors for early mesoderm identity. The role of the β-catenin mechanosensitive pathway in mesoderm identity has been conserved over the large evolutionary distance separating zebrafish and Drosophila. This suggests mesoderm mechanical induction dating back to at least the last bilaterian common ancestor more than 570 million years ago, the period during which mesoderm is thought to have emerged