title: The microcephaly protein Asp regulates neuroepithelium morphogenesis by controlling the spatial distribution of myosin II.
abstract: Mutations in ASPM are the most frequent cause of microcephaly, a disorder characterized by reduced brain size at birth. ASPM is recognized as a major regulator of brain size, yet its role during neural development remains poorly understood. Moreover, the role of ASPM proteins in invertebrate brain morphogenesis has never been investigated. Here, we characterized the function of the Drosophila ASPM orthologue, Asp, and found that asp mutants present severe defects in brain size and neuroepithelium morphogenesis. We show that size reduction depends on the mitotic function of Asp, whereas regulation of tissue shape depends on an uncharacterized function. Asp interacts with myosin II regulating its polarized distribution along the apico-basal axis. In the absence of Asp, mislocalization of myosin II results in interkinetic nuclear migration and tissue architecture defects. We propose that Asp regulates neuroepithelium morphogenesis through myosin-II-mediated structural and mechanical processes to maintain force balance and tissue cohesiveness.
authors.affiliation: UMR144, CNRS- Institut Curie, 12 rue Lhomond, 75005 Paris, France.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Rujano
authors.forename: Luis
authors.initials: L
authors.lastname: Sanchez-Pulido
authors.forename: Carole
authors.initials: C
authors.lastname: Pennetier
authors.forename: Gaelle
authors.initials: G
authors.lastname: le Dez
authors.forename: Renata
authors.initials: R
authors.lastname: Basto
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D029721:Drosophila Proteins / Q000502:physiology*; D004331:Drosophila melanogaster; D004848:Epithelium / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000502:physiology*; D009024:Morphogenesis / Q000502:physiology*; D024462:Myosin Type II / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D008869:Microtubule-Associated Proteins; C106174:asp protein, Drosophila; D024462:Myosin Type II