title: Autophagy is required for efficient meiosis progression and proper meiotic chromosome segregation in fission yeast.
abstract: Autophagy is a conserved intracellular degradation system, which contributes to development and differentiation of various organisms. Yeast cells undergo meiosis under nitrogen-starved conditions and require autophagy for meiosis initiation. However, the precise roles of autophagy in meiosis remain unclear. Here, we show that autophagy is required for efficient meiosis progression and proper meiotic chromosome segregation in fission yeast. Autophagy-defective strains bearing a mutation in the autophagy core factor gene atg1, atg7, or atg14 exhibit deformed nuclear structures during meiosis. These mutant cells require an extracellular nitrogen supply for meiosis progression following their entry into meiosis and show delayed meiosis progression even with a nitrogen supply. In addition, they show frequent chromosome dissociation from the spindle together with spindle overextension, forming extra nuclei. Furthermore, Aurora kinase, which regulates chromosome segregation and spindle elongation, is significantly increased at the centromere and spindle in the mutant cells. Aurora kinase down-regulation eliminated delayed initiation of meiosis I and II, chromosome dissociation, and spindle overextension, indicating that increased Aurora kinase activity may cause these aberrances in the mutant cells. Our findings show a hitherto unrecognized relationship of autophagy with the nuclear structure, regulation of cell cycle progression, and chromosome segregation in meiosis.
authors.affiliation: Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.
authors.forename: Hirotada
authors.initials: H
authors.lastname: Matsuhara
authors.affiliation: Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.|Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.
authors.forename: Ayumu
authors.initials: A
authors.lastname: Yamamoto
mesh_terms: D000705:Anaphase / Q000187:drug effects; D064127:Aurora Kinases / Q000378:metabolism; D001343:Autophagy / Q000187:drug effects / Q000235:genetics; D002467:Cell Nucleus / Q000187:drug effects / Q000473:pathology; D002503:Centromere / Q000187:drug effects / Q000378:metabolism; D020090:Chromosome Segregation / Q000187:drug effects; D003001:Cloning, Molecular; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D017344:Genes, Insect; D042541:Intracellular Space / Q000378:metabolism; D059566:M Phase Cell Cycle Checkpoints / Q000187:drug effects; D008540:Meiosis / Q000187:drug effects / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009584:Nitrogen / Q000494:pharmacology; D010641:Phenotype; D012568:Schizosaccharomyces / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism; D008941:Spindle Apparatus / Q000187:drug effects / Q000378:metabolism; D013172:Spores, Fungal / Q000187:drug effects / Q000502:physiology
chemical_list: D029702:Schizosaccharomyces pombe Proteins; D064127:Aurora Kinases; D009584:Nitrogen