title: Procentriole assembly without centriole disengagement - a paradox of male gametogenesis.
abstract: Disengagement of parent centrioles represents the licensing process to restrict centriole duplication exactly once during the cell cycle. However, we provide compelling evidence that this general rule is overridden in insect gametogenesis, when distinct procentrioles are generated during prophase of the first meiosis while parent centrioles are still engaged. Moreover, the number of procentrioles increases during the following meiotic divisions, and up to four procentrioles were found at the base of each mother centriole. However, procentrioles fail to organize a complete set of A-tubules and are thus unable to function as a template for centriole formation. Such a system, in which procentrioles form but halt growth, represents a unique model to analyze the process of cartwheel assembly and procentriole formation.
authors.affiliation: Department of Life Sciences, University of Siena, Via A. Moro 4, 53100 Siena, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Gottardo
authors.affiliation: Department of Life Sciences, University of Siena, Via A. Moro 4, 53100 Siena, Italy callaini@unisi.it.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Callaini
authors.affiliation: Department of Life Sciences, University of Siena, Via A. Moro 4, 53100 Siena, Italy.
authors.forename: Maria Giovanna
authors.initials: MG
authors.lastname: Riparbelli
mesh_terms: D000818:Animals; D002080:Butterflies / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D002502:Centrioles / Q000378:metabolism*; D008297:Male; D008938:Mitosis; D013090:Spermatocytes / Q000166:cytology / Q000378:metabolism; D013091:Spermatogenesis
keywords: Butterfly; Cartwheel; Centriole duplication; Procentrioles