title: Central topography of cranial motor nuclei controlled by differential cadherin expression.
abstract: Neuronal nuclei are prominent, evolutionarily conserved features of vertebrate central nervous system (CNS) organization. Nuclei are clusters of soma of functionally related neurons and are located in highly stereotyped positions. Establishment of this CNS topography is critical to neural circuit assembly. However, little is known of either the cellular or molecular mechanisms that drive nucleus formation during development, a process termed nucleogenesis. Brainstem motor neurons, which contribute axons to distinct cranial nerves and whose functions are essential to vertebrate survival, are organized exclusively as nuclei. Cranial motor nuclei are composed of two main classes, termed branchiomotor/visceromotor and somatomotor. Each of these classes innervates evolutionarily distinct structures, for example, the branchial arches and eyes, respectively. Additionally, each class is generated by distinct progenitor cell populations and is defined by differential transcription factor expression; for example, Hb9 distinguishes somatomotor from branchiomotor neurons. We characterized the time course of cranial motornucleogenesis, finding that despite differences in cellular origin, segregation of branchiomotor and somatomotor nuclei occurs actively, passing through a phase of each being intermingled. We also found that differential expression of cadherin cell adhesion family members uniquely defines each motor nucleus. We show that cadherin expression is critical to nucleogenesis as its perturbation degrades nucleus topography predictably.
authors.affiliation: Research Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Marc
authors.initials: M
authors.lastname: Astick
authors.affiliation: Research Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Kristina
authors.initials: K
authors.lastname: Tubby
authors.affiliation: Research Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Waleed M
authors.initials: WM
authors.lastname: Mubarak
authors.affiliation: MRC Centre for Developmental Neurobiology, 4(th) Floor New Hunt's House, Kings College, Guy's Campus, London SE1 1UL, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Guthrie
authors.affiliation: Research Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK. Electronic address: stephen.price@ucl.ac.uk.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Price
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D001369:Axons / Q000502:physiology / Q000648:ultrastructure; D001933:Brain Stem / Q000378:metabolism; D015820:Cadherins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D002642:Chick Embryo; D003391:Cranial Nerves / Q000166:cytology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D009046:Motor Neurons / Q000166:cytology / Q000378:metabolism*; D014714:Vertebrates / Q000378:metabolism
chemical_list: D030161:Avian Proteins; D015820:Cadherins