title: Mechanical forces drive neuroblast morphogenesis and are required for epidermal closure.
abstract: Tissue morphogenesis requires myosin-dependent events such as cell shape changes and migration to be coordinated between cells within a tissue, and/or with cells from other tissues. However, few studies have investigated the simultaneous morphogenesis of multiple tissues in vivo. We found that during Caenorhabditis elegans ventral enclosure, when epidermal cells collectively migrate to cover the ventral surface of the embryo, the underlying neuroblasts (neuronal precursor cells) also undergo morphogenesis. We found that myosin accumulates as foci along the junction-free edges of the ventral epidermal cells to form a ring, whose closure is myosin-dependent. We also observed the accumulation of myosin foci and the adhesion junction proteins E-cadherin and α-catenin in the underlying neuroblasts. Myosin may help to reorganize a subset of neuroblasts into a rosette-like pattern, and decrease their surface area as the overlying epidermal cells constrict. Since myosin is required in the neuroblasts for ventral enclosure, we propose that mechanical forces in the neuroblasts influence constriction of the overlying epidermal cells. In support of this model, disrupting neuroblast cell division or altering their fate influences myosin localization in the overlying epidermal cells. The coordination of myosin-dependent events and forces between cells in different tissues could be a common theme for coordinating morphogenetic events during metazoan development.
authors.affiliation: Department of Biology, Concordia University, Montreal, Quebec, Canada.
authors.forename: Denise
authors.initials: D
authors.lastname: Wernike
authors.affiliation: Department of Biology, Concordia University, Montreal, Quebec, Canada.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Biology, Concordia University, Montreal, Quebec, Canada.
authors.forename: Karina
authors.initials: K
authors.lastname: Mastronardi
authors.affiliation: Department of Biology, Concordia University, Montreal, Quebec, Canada.
authors.forename: Neetha
authors.initials: N
authors.lastname: Makil
authors.affiliation: Department of Biology, Concordia University, Montreal, Quebec, Canada. Electronic address: alisa.piekny@concordia.ca.
authors.forename: Alisa
authors.initials: A
authors.lastname: Piekny
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001696:Biomechanical Phenomena; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D002465:Cell Movement; D049109:Cell Proliferation; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D004817:Epidermis / Q000196:embryology / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000379:methods; D009024:Morphogenesis; D009154:Mutation; D009218:Myosins / Q000235:genetics / Q000378:metabolism; D058953:Neural Stem Cells / Q000378:metabolism*; D034622:RNA Interference; D059008:Time-Lapse Imaging / Q000379:methods; D051178:alpha Catenin / Q000235:genetics / Q000378:metabolism
chemical_list: D015820:Cadherins; D029742:Caenorhabditis elegans Proteins; D008164:Luminescent Proteins; D051178:alpha Catenin; D009218:Myosins
keywords: Adhesion junctions; Anillin; C. elegans; Cell migration; Epidermal morphogenesis; Myosin; Neuronal development; RhoA