Epithelial coating controls mesenchymal shape change through tissue-positioning effects and reduction of surface-minimizing tension.
Signalling between mesenchymal and epithelial cells has a profound influence on organ morphogenesis. However, less is known about the mechanical function of epithelial-mesenchymal interactions. Here, we describe two principal effects by which epithelia can regulate shape changes in mesenchymal cell aggregates. We propose that during formation of the embryonic body axis, the epithelial layer relieves surface minimizing tensions that would force cell aggregates into a spherical shape, and controls the serial arrangement of cell populations along the axis. The combined effects permit the tissue to deviate from a spherical form and to elongate.
Ninomiya
Hiromasa
H
Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario M5S 3G5, Canada.
Winklbauer
Rudolf
R
D028341:Activins / Q000494:pharmacology; D000818:Animals; D019070:Cell Lineage / Q000187:drug effects; D004475:Ectoderm / Q000166:cytology / Q000196:embryology; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology*; D004847:Epithelial Cells / Q000166:cytology*; D004848:Epithelium / Q000196:embryology; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008648:Mesoderm / Q000166:cytology / Q000196:embryology*; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis
D029867:Xenopus Proteins; D028341:Activins