Cellular dynamics of epithelial clefting during branching morphogenesis of the mouse submandibular gland

We cultured the rudimental submandibular gland (SMG) of mice with a non–cell‐permeable fluorescent tracer, and observed cell behavior during epithelial branching morphogenesis using confocal time‐lapse microscopy. We traced movements of individual cells as shadowgraph movies. Individual epithelial cells migrated dynamically but erratically. The epithelial cleft extended by wiggling and separated a cluster of cells into two buds during branching. We examined the ultrastructure of the clefts in SMG rudiments treated with the laminin peptide A5G77f, which induces epithelial clefting. A short cytoplasmic shelf with a core of microfilaments was found at the deep end of the cleft. We propose that epithelial clefting involves a dynamic movement of cells at the base of the cleft, and the formation of a shelf within a cleft cell. The shelf might form a matrix attachment point at the base of the cleft with a core of microfilaments driving cleft elongation. Developmental Dynamics 239:1739–1747, 2010. © 2010 Wiley‐Liss, Inc.

[1]  Martin Raff,et al.  Cell Junctions, Cell Adhesion, and the Extracellular Matrix , 2002 .

[2]  B. Spooner,et al.  Collagen involvement in branching morphogenesis of embryonic lung and salivary gland. , 1980, Developmental biology.

[3]  M. Bernfield,et al.  ACID MUCOPOLYSACCHARIDE (GLYCOSAMINOGLYCAN) AT THE EPITHELIAL-MESENCHYMAL INTERFACE OF MOUSE EMBRYO SALIVARY GLANDS , 1972, The Journal of cell biology.

[4]  S. Yamashina,et al.  Reconstruction of the basement membrane in a cultured submandibular gland , 2004, Anatomy and Embryology.

[5]  Melinda Larsen,et al.  Fibronectin requirement in branching morphogenesis , 2003, Nature.

[6]  Y. Fukuda,et al.  The role of interstitial collagens in cleft formation of mouse embryonic submandibular gland during initial branching. , 1988, Development.

[7]  L. Mahadevan,et al.  Cell shape changes indicate a role for extrinsic tensile forces in Drosophila germ-band extension , 2009, Nature Cell Biology.

[8]  H. Kasai,et al.  A new quantitative (two‐photon extracellular polar‐tracer imaging‐based quantification (TEPIQ)) analysis for diameters of exocytic vesicles and its application to mouse pancreatic islets , 2005, The Journal of physiology.

[9]  J. Kishi,et al.  Accumulation of collagen III at the cleft points of developing mouse submandibular epithelium. , 1988, Development.

[10]  M. Nomizu,et al.  Chain-specific heparin-binding sequences in the laminin alpha chain LG45 modules. , 2009, Biochemistry.

[11]  A. Segawa.  Measurement of secretion in confocal microscopy. , 1999, Methods in enzymology.

[12]  M. Kashimata,et al.  Epidermal growth factor system is a physiological regulator of development of the mouse fetal submandibular gland and regulates expression of the α6‐integrin subunit , 1997 .

[13]  A Sue Menko,et al.  Diverse roles of E‐cadherin in the morphogenesis of the submandibular gland: Insights into the formation of acinar and ductal structures , 2008, Developmental dynamics : an official publication of the American Association of Anatomists.

[14]  P Wadsworth,et al.  Observation and quantification of individual microtubule behavior in vivo: microtubule dynamics are cell-type specific , 1993, The Journal of cell biology.

[15]  N. K. Wessells,et al.  Microfilaments in Cellular and Developmental Processes , 1971, Science.

[16]  Y. Nakanishi,et al.  Epithelial morphogenesis in mouse embryonic submandibular gland: Its relationships to the tissue organization of epithelium and mesenchyme , 1997, Development, growth & differentiation.

[17]  H. Nogawa.  Determination of the curvature of epithelial cell mass by mesenchyme in branching morphogenesis of mouse salivary gland. , 1983, Journal of embryology and experimental morphology.

[18]  M. Coughlin,et al.  Early development of parasympathetic nerves in the mouse submandibular gland. , 1975, Developmental biology.

[19]  Frank Costantini,et al.  Real-time analysis of ureteric bud branching morphogenesis in vitro. , 2004, Developmental biology.

[20]  A. Utani,et al.  Biological Activities of Homologous Loop Regions in the Laminin α Chain G Domains* , 2003, Journal of Biological Chemistry.

[21]  M. Hoffman,et al.  Salivary gland branching morphogenesis. , 2006, Differentiation; research in biological diversity.

[22]  Toru Hayashi,et al.  Signaling pathways activated by epidermal growth factor receptor or fibroblast growth factor receptor differentially regulate branching morphogenesis in fetal mouse submandibular glands , 2008, Development, growth & differentiation.

[23]  L. Sulak,et al.  Myosin-dependent junction remodelling controls planar cell intercalation and axis elongation , 2004, Nature.

[24]  Andrew J Ewald,et al.  Collective epithelial migration and cell rearrangements drive mammary branching morphogenesis. , 2008, Developmental cell.

[25]  N. K. Wessells,et al.  Effects of cytochalasin B upon microfilaments involved in morphogenesis of salivary epithelium. , 1970, Proceedings of the National Academy of Sciences of the United States of America.

[26]  E W Gresik,et al.  Epidermal growth factor system is a physiological regulator of development of the mouse fetal submandibular gland and regulates expression of the alpha6-integrin subunit. , 1997, Developmental dynamics : an official publication of the American Association of Anatomists.

[27]  Y. Nakanishi,et al.  Mechanical aspects of the mesenchymal influence on epithelial branching morphogenesis of mouse salivary gland , 1987 .

[28]  Pekka Lappalainen,et al.  Stress fibers are generated by two distinct actin assembly mechanisms in motile cells , 2006, The Journal of cell biology.

[29]  S. Yamashina,et al.  Role for laminin-α5 chain LG4 module in epithelial branching morphogenesis , 2003 .

[30]  Melinda Larsen,et al.  Cell and fibronectin dynamics during branching morphogenesis , 2006, Journal of Cell Science.

[31]  A. Utani,et al.  Biological activities of homologous loop regions in the laminin alpha chain G domains. , 2003, The Journal of biological chemistry.

[32]  Melinda Larsen,et al.  Identification of a mechanochemical checkpoint and negative feedback loop regulating branching morphogenesis. , 2009, Developmental biology.

[33]  S. Yamashina,et al.  Distribution of alpha 6 integrin subunit in developing mouse submandibular gland. , 1993, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[34]  H Nogawa,et al.  Substitution for mesenchyme by basement-membrane-like substratum and epidermal growth factor in inducing branching morphogenesis of mouse salivary epithelium. , 1991, Development.

[35]  S. Yamashina,et al.  Salivary gland morphogenesis and basement membranes , 2005, Anatomical science international.