title: Csm4, in collaboration with Ndj1, mediates telomere-led chromosome dynamics and recombination during yeast meiosis.
abstract: Chromosome movements are a general feature of mid-prophase of meiosis. In budding yeast, meiotic chromosomes exhibit dynamic movements, led by nuclear envelope (NE)-associated telomeres, throughout the zygotene and pachytene stages. Zygotene motion underlies the global tendency for colocalization of NE-associated chromosome ends in a "bouquet." In this study, we identify Csm4 as a new molecular participant in these processes and show that, unlike the two previously identified components, Ndj1 and Mps3, Csm4 is not required for meiosis-specific telomere/NE association. Instead, it acts to couple telomere/NE ensembles to a force generation mechanism. Mutants lacking Csm4 and/or Ndj1 display the following closely related phenotypes: (i) elevated crossover (CO) frequencies and decreased CO interference without abrogation of normal pathways; (ii) delayed progression of recombination, and recombination-coupled chromosome morphogenesis, with resulting delays in the MI division; and (iii) nondisjunction of homologs at the MI division for some reason other than absence of (the obligatory) CO(s). The recombination effects are discussed in the context of a model where the underlying defect is chromosome movement, the absence of which results in persistence of inappropriate chromosome relationships that, in turn, results in the observed mutant phenotypes.
authors.affiliation: Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA.
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Wanat
authors.forename: Keun P
authors.initials: KP
authors.lastname: Kim
authors.forename: Romain
authors.initials: R
authors.lastname: Koszul
authors.forename: Sarah
authors.initials: S
authors.lastname: Zanders
authors.forename: Beth
authors.initials: B
authors.lastname: Weiner
authors.forename: Nancy
authors.initials: N
authors.lastname: Kleckner
authors.forename: Eric
authors.initials: E
authors.lastname: Alani
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D020090:Chromosome Segregation; D015825:Chromosomes, Fungal / Q000235:genetics*; D003433:Crosses, Genetic; D008540:Meiosis; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009685:Nuclear Envelope / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D000089804:Shelterin Complex; D016615:Telomere / Q000235:genetics* / Q000378:metabolism; D034501:Telomere-Binding Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: C530079:CSM4 protein, S cerevisiae; D018797:Cell Cycle Proteins; D008565:Membrane Proteins; C433703:Ndj1 protein, S cerevisiae; C440829:RAP1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins; D014157:Transcription Factors