Meiotic telomere clustering requires actin for its formation and cohesin for its resolution.
In diploid organisms, meiosis reduces the chromosome number by half during the formation of haploid gametes. During meiotic prophase, telomeres transiently cluster at a limited sector of the nuclear envelope (bouquet stage) near the spindle pole body (SPB). Cohesin is a multisubunit complex that contributes to chromosome segregation in meiosis I and II divisions. In yeast meiosis, deficiency for Rec8 cohesin subunit induces telomere clustering to persist, whereas telomere cluster-SPB colocalization is defective. These defects are rescued by expressing the mitotic cohesin Scc1 in rec8delta meiosis, whereas bouquet-stage exit is independent of Cdc5 pololike kinase. An analysis of living Saccharomyces cerevisiae meiocytes revealed highly mobile telomeres from leptotene up to pachytene, with telomeres experiencing an actin- but not microtubule-dependent constraint of mobility during the bouquet stage. Our results suggest that cohesin is required for exit from actin polymerization-dependent telomere clustering and for linking the SPB to the telomere cluster in synaptic meiosis.
Trelles-Sticken
Edgar
E
Max-Planck-Institute for Molecular Genetics, D-14195 Berlin, Germany.
Adelfalk
Caroline
C
Loidl
Josef
J
Scherthan
Harry
H
D000199:Actins / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism / Q000502:physiology*; D002467:Cell Nucleus / Q000235:genetics / Q000502:physiology; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D015825:Chromosomes, Fungal / Q000502:physiology; D005656:Fungal Proteins / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D008540:Meiosis; D008870:Microtubules / Q000502:physiology; D009154:Mutation; D009685:Nuclear Envelope / Q000502:physiology; D009687:Nuclear Proteins / Q000502:physiology*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D000089804:Shelterin Complex; D008941:Spindle Apparatus; D016615:Telomere / Q000235:genetics / Q000502:physiology*; D034501:Telomere-Binding Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D000097722:Cohesins
D000199:Actins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D005656:Fungal Proteins; D049452:Green Fluorescent Proteins; D009687:Nuclear Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D029701:Saccharomyces cerevisiae Proteins; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins; D014157:Transcription Factors; D000097722:Cohesins; C440829:RAP1 protein, S cerevisiae; C502898:REC8 protein, S cerevisiae; C081927:CDC5 protein, S cerevisiae