title: Forces directing germ-band extension in Drosophila embryos.
abstract: Body axis elongation by convergent extension is a conserved developmental process found in all metazoans. Drosophila embryonic germ-band extension is an important morphogenetic process during embryogenesis, by which the length of the germ-band is more than doubled along the anterior-posterior axis. This lengthening is achieved by typical convergent extension, i.e. narrowing the lateral epidermis along the dorsal-ventral axis and simultaneous extension along the anterior-posterior axis. Germ-band extension is largely driven by cell intercalation, whose directionality is determined by the planar polarity of the tissue and ultimately by the anterior-posterior patterning system. In addition, extrinsic tensile forces originating from the invaginating endoderm induce cell shape changes, which transiently contribute to germ-band extension. Here, we review recent progress in understanding of the role of mechanical forces in germ-band extension.
authors.affiliation: Institute for Developmental Biochemistry, Medical School, University of Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany.
authors.forename: Deqing
authors.initials: D
authors.lastname: Kong
authors.affiliation: Department of Nonlinear Dynamics, Max Planck Institute for Dynamics and Self-Organisation, Faculty of Physics, Bernstein Center for Computational Neuroscience, University of Göttingen, Am Faßberg 17, 37077 Göttingen, Germany.
authors.forename: Fred
authors.initials: F
authors.lastname: Wolf
authors.affiliation: Institute for Developmental Biochemistry, Medical School, University of Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany. Electronic address: jgrossh@gwdg.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Großhans
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001696:Biomechanical Phenomena; D019521:Body Patterning / Q000235:genetics; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D020013:Calcium Signaling; D002455:Cell Division; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian; D047108:Embryonic Development / Q000235:genetics*; D000078404:Epidermal Cells; D004817:Epidermis / Q000196:embryology* / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D015233:Models, Statistical
chemical_list: D000199:Actins; D015820:Cadherins; D029721:Drosophila Proteins; C501889:shg protein, Drosophila
keywords: Cell intercalation; Drosophila; Forces; Germ-band extension