title: Differential regulation of node formation, nodal ciliogenesis and cilia positioning by Noto and Foxj1.
abstract: The mouse transcription factor Noto is expressed in the node and controls node morphogenesis, formation of nodal cilia and left-right asymmetry. Noto acts upstream of Foxj1, which regulates ciliogenesis in other mouse tissues. However, the significance of Foxj1 for the formation of cilia in the mouse node is unclear; in non-amniote species Foxj1 is required for ciliogenesis in the structures equivalent to the node. Here, we analyzed nodes, nodal cilia and nodal flow in mouse embryos in which we replaced the Noto-coding sequence with that of Foxj1, or in embryos that were deficient for Foxj1. We show that Foxj1 expressed from the Noto locus is functional and restores the formation of structurally normal motile cilia in the absence of Noto. However, Foxj1 is not sufficient for the correct positioning of cilia on the cell surface within the plane of the nodal epithelium, and cannot restore normal node morphology. We also show that Foxj1 is essential for ciliogenesis upstream of Rfx3 in the node. Thus, the function of Foxj1 in vertebrate organs of asymmetry is conserved, and Noto regulates node morphogenesis and the posterior localization of cilia on node cells independently of Foxj1.
authors.affiliation: Institute for Molecular Biology, Medizinische Hochschule Hannover, Carl-Neuberg-Strasse 1, Hannover, Germany.
authors.forename: Leonie
authors.initials: L
authors.lastname: Alten
authors.forename: Karin
authors.initials: K
authors.lastname: Schuster-Gossler
authors.forename: Anja
authors.initials: A
authors.lastname: Beckers
authors.forename: Stephanie
authors.initials: S
authors.lastname: Groos
authors.forename: Bärbel
authors.initials: B
authors.lastname: Ulmer
authors.forename: Jan
authors.initials: J
authors.lastname: Hegermann
authors.forename: Matthias
authors.initials: M
authors.lastname: Ochs
authors.forename: Achim
authors.initials: A
authors.lastname: Gossler
mesh_terms: D000483:Alleles; D000818:Animals; D002923:Cilia / Q000502:physiology*; D004848:Epithelium / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D005838:Genotype; D018398:Homeodomain Proteins / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D018715:Microscopy, Video / Q000379:methods; D008954:Models, Biological; D008957:Models, Genetic; D009024:Morphogenesis / Q000235:genetics; D054240:Primitive Streak / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: C481963:FOXJ1 protein, mouse; D051858:Forkhead Transcription Factors; D018398:Homeodomain Proteins; C489656:Not protein, mouse; D014157:Transcription Factors