title: Asymmetric morphology of the cells comprising the inner and outer bending sides of the murine duodenojejunal flexure.
abstract: The asymmetric shape of component cells determines the asymmetric features of developing organs. Here, we focused on the murine duodenojejunal flexure (DJF), which bends without affecting the mesentery, and analyzed the morphological asymmetries of the mucosal epithelium and gut wall cells between the inner and outer bending sides at embryonic days 10.75-11.75. In the mucosal epithelium, the cell shape and the expression of epithelial markers (Cdx2, E-cadherin) showed no differences between the two DJF sides. In contrast, the gut wall cells comprising the inner and outer sides of the DJF were elongated along the inner-outer axis and perpendicular to this axis, respectively. Furthermore, the gut wall cells in the outer side possessed cytoplasmic processes connecting cells via adherens junctions, but those in the inner side were attached via adherens junctions of juxtaposed cell bodies and were relatively more crowded. In immunohistochemistry experiments, there was no remarkable difference in the positive reactions of markers for mesenchyme (vimentin), smooth muscle cells (αSMA), endothelial cells (LYVE-1, CD34), and undifferentiated neurons (Sox10) between the DJF sides. Interestingly, Tuj1-positive cells, indicating differentiated neurons, were observed in the middle layer of the gut wall, and these cells were significantly more abundant and tended to be larger in the inner side than in the outer side of the DJF. In conclusion, we clarified the asymmetries of gut wall cell morphology and neural differentiation between the inner and outer sides of the DJF. These characteristics of the developing murine DJF indicate its asymmetric formation.
authors.affiliation: Laboratory of Anatomy, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo, 060-0818, Japan.
authors.forename: Sawa
authors.initials: S
authors.lastname: Onouchi
authors.forename: Osamu
authors.initials: O
authors.lastname: Ichii
authors.forename: Saori
authors.initials: S
authors.lastname: Otsuka-Kanazawa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kon
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000378:metabolism*; D004386:Duodenum / Q000166:cytology* / Q000196:embryology*; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology / Q000196:embryology; D007583:Jejunum / Q000166:cytology* / Q000196:embryology*; D051379:Mice; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism
chemical_list: D000943:Antigens, Differentiation