title: Synaptonemal complex components promote centromere pairing in pre-meiotic germ cells.
abstract: Mitosis and meiosis are two distinct cell division programs. During mitosis, sister chromatids separate, whereas during the first meiotic division, homologous chromosomes pair and then segregate from each other. In most organisms, germ cells do both programs sequentially, as they first amplify through mitosis, before switching to meiosis to produce haploid gametes. Here, we show that autosomal chromosomes are unpaired at their centromeres in Drosophila germline stem cells, and become paired during the following four mitosis of the differentiating daughter cell. Surprisingly, we further demonstrate that components of the central region of the synaptonemal complex are already expressed in the mitotic region of the ovaries, localize close to centromeres, and promote de novo association of centromeres. Our results thus show that meiotic proteins and meiotic organization of centromeres, which are key features to ensure reductional segregation, are laid out in amplifying germ cells, before meiosis has started.
authors.affiliation: Department of Genetics and Developmental Biology, Institut Curie, Paris, France ; CNRS UMR3215; Inserm U934, Paris, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Christophorou
authors.affiliation: Department of Genetics and Developmental Biology, Institut Curie, Paris, France ; CNRS UMR3215; Inserm U934, Paris, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rubin
authors.affiliation: Department of Genetics and Developmental Biology, Institut Curie, Paris, France ; CNRS UMR3215; Inserm U934, Paris, France.
authors.forename: Jean-René
authors.initials: JR
authors.lastname: Huynh
mesh_terms: D000818:Animals; D002503:Centromere / Q000235:genetics*; D002842:Chromatids / Q000235:genetics; D023902:Chromosome Pairing / Q000235:genetics*; D020090:Chromosome Segregation; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics*; D005854:Germ Cells / Q000166:cytology; D008540:Meiosis / Q000235:genetics*; D008938:Mitosis; D012854:Sister Chromatid Exchange / Q000235:genetics; D013573:Synaptonemal Complex / Q000235:genetics*