title: PAPC mediates self/non-self-distinction during Snail1-dependent tissue separation.
abstract: Cleft-like boundaries represent a type of cell sorting boundary characterized by the presence of a physical gap between tissues. We studied the cleft-like ectoderm-mesoderm boundary in Xenopus laevis and zebrafish gastrulae. We identified the transcription factor Snail1 as being essential for tissue separation, showed that its expression in the mesoderm depends on noncanonical Wnt signaling, and demonstrated that it enables paraxial protocadherin (PAPC) to promote tissue separation through two novel functions. First, PAPC attenuates planar cell polarity signaling at the ectoderm-mesoderm boundary to lower cell adhesion and facilitate cleft formation. Second, PAPC controls formation of a distinct type of adhesive contact between mesoderm and ectoderm cells that shows properties of a cleft-like boundary at the single-cell level. It consists of short stretches of adherens junction-like contacts inserted between intermediate-sized contacts and large intercellular gaps. These roles of PAPC constitute a self/non-self-recognition mechanism that determines the site of boundary formation at the interface between PAPC-expressing and -nonexpressing cells.
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5.
authors.forename: Olivia
authors.initials: O
authors.lastname: Luu
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5.
authors.forename: Erich W
authors.initials: EW
authors.lastname: Damm
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5.
authors.forename: Serge E
authors.initials: SE
authors.lastname: Parent
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5.
authors.forename: Debanjan
authors.initials: D
authors.lastname: Barua
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5.
authors.forename: Tamara H L
authors.initials: TH
authors.lastname: Smith
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5.
authors.forename: Jason W H
authors.initials: JW
authors.lastname: Wen
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5.
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Lepage
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5.
authors.forename: Martina
authors.initials: M
authors.lastname: Nagel
authors.affiliation: Zoological Institute, University of Cologne, D-50674 Cologne, Germany.
authors.forename: Hady
authors.initials: H
authors.lastname: Ibrahim-Gawel
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5.
authors.forename: Yunyun
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5 r.winklbauer@utoronto.ca ashley.bruce@utoronto.ca.
authors.forename: Ashley E E
authors.initials: AE
authors.lastname: Bruce
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5 r.winklbauer@utoronto.ca ashley.bruce@utoronto.ca.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Winklbauer
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D019521:Body Patterning; D015820:Cadherins / Q000502:physiology*; D002448:Cell Adhesion; D016764:Cell Polarity; D005775:Gastrula / Q000196:embryology / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism; D000091363:Protocadherins; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D014157:Transcription Factors / Q000502:physiology*; D029867:Xenopus Proteins / Q000378:metabolism / Q000502:physiology*; D014982:Xenopus laevis; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000502:physiology
chemical_list: D000199:Actins; D015820:Cadherins; C492040:Fzd7 protein, Xenopus; C117635:Pcdh8 protein, Xenopus; D000091363:Protocadherins; D043562:Receptors, G-Protein-Coupled; C000597965:Snai1 protein, Xenopus; D014157:Transcription Factors; D029867:Xenopus Proteins; D029961:Zebrafish Proteins