title: Are dendrites in Drosophila homologous to vertebrate dendrites?
abstract: Dendrites represent arborising neurites in both vertebrates and invertebrates. However, in vertebrates, dendrites develop on neuronal cell bodies, whereas in higher invertebrates, they arise from very different neuronal structures, the primary neurites, which also form the axons. Is this anatomical difference paralleled by principal developmental and/or physiological differences? We address this question by focussing on one cellular model, motorneurons of Drosophila and characterise the compartmentalisation of these cells. We find that motorneuronal dendrites of Drosophila share with typical vertebrate dendrites that they lack presynaptic but harbour postsynaptic proteins, display calcium elevation upon excitation, have distinct cytoskeletal features, develop later than axons and are preceded by restricted localisation of Par6-complex proteins. Furthermore, we demonstrate in situ and culture that Drosophila dendrites can be shifted from the primary neurite to their soma, i.e. into vertebrate-like positions. Integrating these different lines of argumentation, we propose that dendrites in vertebrates and higher invertebrates have a common origin, and differences in dendrite location can be explained through translocation of neuronal cell bodies introduced during the evolutionary process by which arthropods and vertebrates diverged from a common urbilaterian ancestor. Implications of these findings for studies of dendrite development, neuronal polarity, transport and evolution are discussed.
authors.affiliation: Faculty of Life Sciences, WTCCMR, The University of Manchester, Oxford Road, Manchester M13 9PT, UK.
authors.forename: Natalia
authors.initials: N
authors.lastname: Sánchez-Soriano
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bottenberg
authors.forename: André
authors.initials: A
authors.lastname: Fiala
authors.forename: Ulrike
authors.initials: U
authors.lastname: Haessler
authors.forename: Afroditi
authors.initials: A
authors.lastname: Kerassoviti
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Knust
authors.forename: Robert
authors.initials: R
authors.lastname: Löhr
authors.forename: Andreas
authors.initials: A
authors.lastname: Prokop
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D005075:Biological Evolution; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology; D002478:Cells, Cultured; D003712:Dendrites / Q000502:physiology*; D004331:Drosophila melanogaster / Q000166:cytology* / Q000235:genetics / Q000502:physiology; D051379:Mice; D009046:Motor Neurons / Q000166:cytology* / Q000502:physiology; D011817:Rabbits; D051381:Rats
chemical_list: D002118:Calcium