title: 9 + 0 and 9 + 2 cilia are randomly dispersed in the mouse node.
abstract: The initial determination of left-right asymmetry is an essential process in embryonic development. In mouse embryo, cilia in the node play an important role generating the nodal flow that subsequently triggers left-right determination in the embryo. Although nodal cilia have historically been thought to have a 9 + 0 axonemal configuration, the existence of 9 + 2 cilia has been reported so far. Because the distribution of those two types of cilia within the node has not yet been reported, we assessed the arrangement of 9 + 0 and 9 + 2 cilia in the node. In this study, we concluded that most of the nodal cilia were 9 + 0 in structure and there were much fewer 9 + 2 cilia than 9 + 0 cilia. Furthermore, the two types of cilia were randomly distributed in the node with no regularity. In addition, we studied the embryonic origin of the crown cells surrounding the node to better understand their identity.
authors.affiliation: Department of Anatomy and Cell Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimo-Kateau, Chuo, Yamanashi 409-3898, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Odate
authors.affiliation: Department of Anatomy and Cell Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimo-Kateau, Chuo, Yamanashi 409-3898, Japan stakeda@yamanashi.ac.jp.
authors.forename: Sen
authors.initials: S
authors.lastname: Takeda
authors.affiliation: Department of Anatomy and Cell Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimo-Kateau, Chuo, Yamanashi 409-3898, Japan.
authors.forename: Keishi
authors.initials: K
authors.lastname: Narita
authors.affiliation: Department of Anatomy and Cell Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimo-Kateau, Chuo, Yamanashi 409-3898, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kawahara
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D002923:Cilia / Q000502:physiology*; D004622:Embryo, Mammalian / Q000033:anatomy & histology*; D047108:Embryonic Development / Q000502:physiology*; D004707:Endoderm / Q000166:cytology / Q000196:embryology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008855:Microscopy, Electron, Scanning / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods; D011247:Pregnancy
keywords: atypical cilia; cilia; crown cell; endoderm; left–right asymmetry; node