title: The slender lobes gene, identified by retarded mushroom body development, is required for proper nucleolar organization in Drosophila.
abstract: The nucleolus dynamically alters its shape through the assembly and disassembly of a variety of nucleolar components in proliferating cells. While the nucleolus is known to function in vital cellular events, little is known about how its components are correctly assembled. Through the analysis of a Drosophila mutant that exhibits a reduced number of mushroom body (MB) neurons in the brain, we reveal that the slender lobes (sle) gene encodes a novel nuclear protein that affects nucleolar organization during development. In sle mutant neuroblasts, the nucleolus was packed more tightly, forming a dense sphere, and the nucleolar proteins fibrillarin and Nop60B were abnormally distributed in the interphase nucleolus. Moreover, another nucleolar marker, Aj1 antigen, was localized to the center of the nucleolus in a manner complementary to the Nop60B distribution, and also formed a large aggregate in the cytoplasm. While developmental defects were limited to a few tissues in sle mutants, including MBs and nurse cells, the altered organization of the nucleolar components were evident in most developing tissues. Therefore, we conclude that Sle is a general factor of nuclear architecture in Drosophila that is required for the correct organization of the nucleolus during development.
authors.affiliation: Riken Center for Developmental Biology, 2-2-3 Minatojima-minami, Chuo, Kobe, Hyogo 650-0047, Japan.
authors.forename: Minako
authors.initials: M
authors.lastname: Orihara-Ono
authors.forename: Emiko
authors.initials: E
authors.lastname: Suzuki
authors.forename: Mai
authors.initials: M
authors.lastname: Saito
authors.forename: Yuka
authors.initials: Y
authors.lastname: Yoda
authors.forename: Toshiro
authors.initials: T
authors.lastname: Aigaki
authors.forename: Chihiro
authors.initials: C
authors.lastname: Hama
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002453:Cell Cycle; D002466:Cell Nucleolus / Q000378:metabolism* / Q000648:ultrastructure; D049109:Cell Proliferation; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology* / Q000235:genetics*; D007150:Immunohistochemistry; D024521:Mushroom Bodies / Q000166:cytology / Q000254:growth & development*; D009154:Mutation; D010641:Phenotype; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D011993:Recombinant Fusion Proteins; C501829:sle protein, Drosophila