title: A Centrin3-dependent, transient, appendage of the mother basal body guides the positioning of the daughter basal body in Paramecium.
abstract: Basal bodies are tightly controlled not only for their time of duplication but also for their movements, which ensure proper division and morphogenesis. However, the mechanisms underlying these movements only begin to be explored. We describe here a novel basal body appendage in Paramecium, the anterior left filament (ALF), which develops transiently from the mother basal body before duplication and disassembles once the new basal body is docked at the surface. By comparing the ultrastructure of dividing wild type cells to that of cells defective in basal body duplication, either by depletion of conserved proteins required for basal body assembly, or by mutation, we showed 1) that assembly of the ALF requires PtCen3p, one of the two basal body specific centrins and 2) that absence of the ALF correlates with a failure of the newly assembled basal bodies to tilt up to their docking site at the surface. This correlation suggests that the function of the ALF consists in anchoring centrin-containing contractile fibers which pull up the new basal body toward its site of docking. The presence in T. thermophila of an ALF-like appendage suggests the conservation of an ancestral mechanism ensuring the coupling of basal body duplication and cell morphogenesis.
authors.affiliation: Polish Academy of Sciences, The Nencki Institute of Experimental Biology, Warsaw, Poland. dziadosz@nencki.gov.pl
authors.forename: Maria
authors.initials: M
authors.lastname: Jerka-Dziadosz
authors.forename: France
authors.initials: F
authors.lastname: Koll
authors.forename: Dorota
authors.initials: D
authors.lastname: Włoga
authors.forename: Delphine
authors.initials: D
authors.lastname: Gogendeau
authors.forename: Nicole
authors.initials: N
authors.lastname: Garreau de Loubresse
authors.forename: Françoise
authors.initials: F
authors.lastname: Ruiz
authors.forename: Stanisław
authors.initials: S
authors.lastname: Fabczak
authors.forename: Janine
authors.initials: J
authors.lastname: Beisson
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D002502:Centrioles / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D002923:Cilia / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D015388:Organelles / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D016805:Paramecium tetraurelia / Q000166:cytology / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D002135:Calcium-Binding Proteins; D002868:Chromosomal Proteins, Non-Histone; D015800:Protozoan Proteins; C056608:caltractin