title: Embryonic origins of hull cells in the flatworm Macrostomum lignano through cell lineage analysis: developmental and phylogenetic implications.
abstract: The development of macrostomid flatworms is of interest for evolutionary developmental biology research because these taxa combine characteristics of the canonical spiral cleavage pattern with significant deviations from this pattern. One such deviation is the formation of hull cells, which surround the remaining embryonic primordium during early development. Using live observations with a 4D microscope system, histology, and 3D reconstructions, we analyzed the ontogeny of these hull cells in the macrostomid model organism Macrostomum lignano. Our cell lineage analysis allowed us to find the precursors of the hull cells in this species. We discuss the relation between macrostomid development and the development of other spiralians and the question of whether hull cells are homologous within rhabditophoran flatworms.
authors.affiliation: Department of Biology, Ghent University, Ghent, Belgium. maxime.willems@ugent.be
authors.forename: Maxime
authors.initials: M
authors.lastname: Willems
authors.forename: Bernhard
authors.initials: B
authors.lastname: Egger
authors.forename: Carsten
authors.initials: C
authors.lastname: Wolff
authors.forename: Stijn
authors.initials: S
authors.lastname: Mouton
authors.forename: Wouter
authors.initials: W
authors.lastname: Houthoofd
authors.forename: Pamela
authors.initials: P
authors.lastname: Fonderie
authors.forename: Marjolein
authors.initials: M
authors.lastname: Couvreur
authors.forename: Tom
authors.initials: T
authors.lastname: Artois
authors.forename: Gaëtan
authors.initials: G
authors.lastname: Borgonie
mesh_terms: D000818:Animals; D001757:Blastomeres / Q000166:cytology; D014419:Turbellaria / Q000145:classification / Q000166:cytology / Q000196:embryology*