title: A role for planar cell polarity during early endoderm morphogenesis.
abstract: The zebrafish endoderm begins to develop at gastrulation stages as a monolayer of cells. The behaviour of the endoderm during gastrulation stages is well understood. However, knowledge of the morphogenic movements of the endoderm during somitogenesis stages, as it forms a mesenchymal rod, is lacking. Here we characterise endodermal development during somitogenesis stages, and describe the morphogenic movements as the endoderm transitions from a monolayer of cells into a mesenchymal endodermal rod. We demonstrate that, unlike the overlying mesoderm, endodermal cells are not polarised during their migration to the midline at early somitogenesis stages. Specifically, we describe the stage at which endodermal cells begin to leave the monolayer, a process we have termed 'midline aggregation'. The planar cell polarity (PCP) signalling pathway is known to regulate mesodermal and ectodermal cell convergence towards the dorsal midline. However, a role for PCP signalling in endoderm migration to the midline during somitogenesis stages has not been established. In this report, we investigate the role for PCP signalling in multiple phases of endoderm development during somitogenesis stages. Our data exclude involvement of PCP signalling in endodermal cells as they leave the monolayer.
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Lee B
authors.initials: LB
authors.lastname: Miles
authors.affiliation: Graduate School of Pharmaceutical sciences, Chiba University, Chuo-ku 260-8675, Japan.
authors.forename: Takamasa
authors.initials: T
authors.lastname: Mizoguchi
authors.affiliation: Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kikuchi
authors.affiliation: School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia heather.verkade@unimelb.edu.au.
authors.forename: Heather
authors.identifier: http://orcid.org/0000-0002-2817-0509
authors.initials: H
authors.lastname: Verkade
keywords: Development; Endoderm; Midline aggregation; Planar cell polarity (PCP); Zebrafish