The article provides a biomechanical analysis of ventral furrow formation in the Drosophila melanogaster embryo. Ventral furrow formation is the first large-scale morphogenetic movement in the fly embryo. It involves deformation of a uniform cellular monolayer formed following cellularisation, and has therefore long been used as a simple system in which to explore the role of mechanics in force...

In epithelial cells, myosin-II-dependent forces regulate many aspects of animal morphogenesis, such as apical constriction, cell intercalation, cell sorting, and the formation and maintenance of the adherens junction. These forces are mainly generated by the circumferential actomyosin belt, which is composed of F-actin-myosin II bundles located along apical cell-cell junctions. Although several...

INTRODUCTION The purpose of this study was to compare the accuracy of working length (WL) measurements by using the Root ZX II, Apex NRG XFR, and Mini Apex Locator with rotary nickel-titanium (NiTi) instruments. METHODS Twenty-eight teeth had their WLs determined with each electronic apex locator (EAL) by using 0.04 taper ProFiles sizes 40-20 in a crown-down technique until WL was reached. Fo...

Cells dividing in the plane of epithelial tissues proceed by polarized constriction actomyosin contractile ring, leading to asymmetric ingression plasma mem brane. Asymmetric cytokinesis results apical positioning ring and ultimately midbody. Studies have indicated that is associated with adherens junctions, whose role maintain tissue cohesion. However, it yet unknown when becomes junctions cel...

During morphogenesis, contraction of the actomyosin cytoskeleton within individual cells drives cell shape changes that fold tissues. Coordination of cytoskeletal contractility is mediated by regulating RhoA GTPase activity. Guanine nucleotide exchange factors (GEFs) activate and GTPase-activating proteins (GAPs) inhibit RhoA activity. Most studies of tissue folding, including apical constricti...

The Arp2/3 complex is important for morphogenesis in various developmental systems, but specific in vivo roles for this complex in cells that move during morphogenesis are not well understood. We have examined cellular roles for Arp2/3 in the Caenorhabditis elegans embryo. In C. elegans, the first morphogenetic movement, gastrulation, is initiated by the internalization of two endodermal precur...

Apical constriction (AC) is a widely utilized mechanism of cell shape change whereby epithelial cells transform from a cylindrical to conical shape,which can facilitatemorphogeneticmovements during embryonic development. Invertebrate epithelial cells undergoing AC depend on the contraction of apical cortex-spanning actomyosin filaments that generate force on the apical junctions and pull them t...

www.landesbioscience.com Cell Cycle 3583 Epithelial cells are organized into polarized sheets that separate distinct compartments of multicellular organisms. Within the epithelial tissue, cells are held together by a set of polarized junctional complexes that regulate adhesion and also separate functionally distinct apical and basolateral membranes. Despite a solid understanding of the establis...