caa a22 4500 477095763 CHVBK 20180405111527.0 cr unu---uuuuu 170330e19960701xx s 000 0 eng 10.1007/BF00196316 doi (NATIONALLICENCE)springer-10.1007/BF00196316 Regional differences in morphogenesis of the neuroepithelium suggest multiple mechanisms of spinal neurulation in the mouse [Elektronische Daten] [Alisa Shum, Andrew Copp] A study of neuroepithelial morphogenesis in the mouse embryo has identified three modes of neural tube formation that occur consecutively as neurulation progresses along the spinal region. The three modes of neurulation differ in the extent to which the neuroepithelium exhibits formation of ‘hinge points', i.e. localised bending owing to reduction in apical surface area. In Mode 1, bending occurs only in the neuroepithelium overlying the notochord, creating a median hinge point. The neural folds remain straight along both apical and basal surfaces, resulting in a neural tube with a slit-shaped lumen. In Mode 2, the neuroepithelium forms paired dorsolateral hinge points, as well as a median hinge point, whereas the remaining portions of the neuroepithelium do not bend. This produces a neural tube with a diamond-shaped lumen. In Mode 3 neurulation, the entire neuroepithelium exhibits bending, so that the cells specific hinge points are not discernible; the resulting neural tube has a circular lumen. The three modes of neurulation are present in all three strains of mice studied: C57BL/6, CBA/Ca and curly tail, a mutant predisposed to neural tube defects. However, curly tail embryos exhibit a delay in transition from Mode 2 to Mode 3, preceding faulty closure of the posterior neuropore. This heterogeneity of neurulation morphogenesis in the mouse embryo indicates that the underlying mechanisms may vary along the body axis. Specifically, we suggest that Mode 1 neurulation is driven largely by forces generated extrinsic to the neuroepithelium, in adjacent tissues, whereas Mode 3 neurulation is dependent primarily on forces generated intrinsic to the neuroepithelium. Down the body axis, there is a gradual decrease in the area of ectoderm involved in neural induction and, as neurulation reaches lower spinal levels, the newly induced neural plate exhibits marked indentation from the time of its first appearance. The transition from primary neurulation (neural folding of Mode 3 type) to secondary neurulation (neural tube formation by cavitation) appears to be a smooth continuation of this trend, with loss of contact between the newly induced neuroepithelium and the outside of the embryo. Springer-Verlag, 1996 Embryo nationallicence Development nationallicence Mutant nationallicence Neural tube nationallicence Neural induction nationallicence Shum Alisa Department of Anatomy, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong aut Copp Andrew Division of Cell and Molecular Biology, Institute of Child Health, University of London, 30 Guilford Street, WC1N 1EH, London, UK aut Anatomy and Embryology Springer-Verlag 194/1(1996-07-01), 65-73 0340-2061 194:1<65 1996 194 429 https://doi.org/10.1007/BF00196316 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00196316 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Shum Alisa Department of Anatomy, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong aut NATIONALLICENCE 700 1- Copp Andrew Division of Cell and Molecular Biology, Institute of Child Health, University of London, 30 Guilford Street, WC1N 1EH, London, UK aut NATIONALLICENCE 773 0- Anatomy and Embryology Springer-Verlag 194/1(1996-07-01), 65-73 0340-2061 194:1<65 1996 194 429 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer