Reference - Detail
|Author||Vuong-Brender TTK, Suman SK, Labouesse M.|
|Title||The apical ECM preserves embryonic integrity and distributes mechanical stress during morphogenesis.|
Epithelia are bound by both basal and apical extracellular matrices (ECM). Although the composition and function of the former have been intensively investigated, less is known about the latter. The embryonic sheath, the ECM apical to the Caenorhabditis elegans embryonic epidermis, has been suggested to promote elongation of the embryo. In an RNAi screen for the components of the sheath, we identified the zona pellucida domain proteins NOAH-1 and NOAH-2. We found that these proteins act in the same pathway, and in parallel to three other putative sheath proteins, the leucine-rich repeat proteins SYM-1, LET-4 and FBN-1/Fibrillin, to ensure embryonic integrity and promote elongation. Laser nano-ablation experiments to map the stress field show that NOAH-1 and NOAH-2, together with PAK-1/p21-activated kinase, maintain and relay the actomyosin-dependent stress generated within the lateral epidermis before muscles become active. Subsequently, loss-of-function experiments show that apical ECM proteins are essential for muscle anchoring and for relaying the mechanical input from muscle contractions, which are essential for elongation. Hence, the apical ECM contributes to morphogenesis by maintaining embryonic integrity and relaying mechanical stress.
|MeSH||Actomyosin / physiology Animals Biomechanical Phenomena Body Patterning / genetics Body Patterning / physiology Caenorhabditis elegans / embryology* Caenorhabditis elegans / genetics Caenorhabditis elegans / physiology Caenorhabditis elegans Proteins / antagonists & inhibitors Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / physiology Extracellular Matrix / physiology* Extracellular Matrix Proteins / antagonists & inhibitors Extracellular Matrix Proteins / genetics Extracellular Matrix Proteins / physiology Genes, Helminth Leucine-Rich Repeat Proteins Models, Biological Morphogenesis / genetics Morphogenesis / physiology* Proteins / antagonists & inhibitors Proteins / genetics Proteins / physiology RNA Interference Stress, Mechanical Zona Pellucida Glycoproteins / antagonists & inhibitors Zona Pellucida Glycoproteins / genetics Zona Pellucida Glycoproteins / physiology|