Meiotic Nuclear Oscillations Are Necessary to Avoid Excessive Chromosome Associations.
Pairing of homologous chromosomes is a crucial step in meiosis, which in fission yeast depends on nuclear oscillations. However, how nuclear oscillations help pairing is unknown. Here, we show that homologous loci typically pair when the spindle pole body is at the cell pole and the nucleus is elongated, whereas they unpair when the spindle pole body is in the cell center and the nucleus is round. Inhibition of oscillations demonstrated that movement is required for initial pairing and that prolonged association of loci leads to mis-segregation. The double-strand break marker Rec25 accumulates in elongated nuclei, indicating that prolonged chromosome stretching triggers recombinatory pathways leading to mis-segregation. Mis-segregation is rescued by overexpression of the Holliday junction resolvase Mus81, suggesting that prolonged pairing results in irresolvable recombination intermediates. We conclude that nuclear oscillations exhibit a dual role, promoting initial pairing and restricting the time of chromosome associations to ensure proper segregation.
Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
Mariola R
MR
Chacón
Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
Petrina
P
Delivani
Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany; Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia. Electronic address: tolic@irb.hr.
Iva M
IM
Tolić
D002467:Cell Nucleus / Q000378:metabolism*; D023902:Chromosome Pairing; D020090:Chromosome Segregation; D015825:Chromosomes, Fungal / Q000378:metabolism*; D056426:Genetic Loci; D049452:Green Fluorescent Proteins / Q000378:metabolism; D045565:Holliday Junction Resolvases; D008540:Meiosis; D012568:Schizosaccharomyces / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism; D064048:Spindle Pole Bodies / Q000378:metabolism; D059008:Time-Lapse Imaging
D029702:Schizosaccharomyces pombe Proteins; D049452:Green Fluorescent Proteins; D045565:Holliday Junction Resolvases
Mus81; Rec25; chromosome missegregation; chromosome pairing; double-strand breaks; horsetail movement; meiosis; meiotic prophase; nuclear oscillations; recombination