The meiotic bouquet promotes homolog interactions and restricts ectopic recombination in Schizosaccharomyces pombe.
Chromosome architecture undergoes extensive, programmed changes as cells enter meiosis. A highly conserved change is the clustering of telomeres at the nuclear periphery to form the "bouquet" configuration. In the fission yeast Schizosaccharomyces pombe the bouquet and associated nuclear movement facilitate initial interactions between homologs. We show that Bqt2, a meiosis-specific protein required for bouquet formation, is required for wild-type levels of homolog pairing and meiotic allelic recombination. Both gene conversion and crossing over are reduced and exhibit negative interference in bqt2Delta mutants, reflecting reduced homolog pairing. While both the bouquet and nuclear movement promote pairing, only the bouquet restricts ectopic recombination (that between dispersed repetitive DNA). We discuss mechanisms by which the bouquet may prevent deleterious translocations by restricting ectopic recombination.
Davis
Luther
L
Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA.
Smith
Gerald R
GR
D023902:Chromosome Pairing / Q000235:genetics; D021901:DNA, Intergenic; D004398:Dyneins / Q000235:genetics / Q000502:physiology; D008540:Meiosis / Q000502:physiology; D008957:Models, Genetic; D009154:Mutation; D011418:Prophase / Q000235:genetics; D011995:Recombination, Genetic / Q000502:physiology*; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000502:physiology; D012689:Sequence Homology, Nucleic Acid; D008941:Spindle Apparatus / Q000502:physiology*; D016615:Telomere / Q000502:physiology; D034501:Telomere-Binding Proteins / Q000235:genetics / Q000502:physiology
C510172:Bqt2 protein, S pombe; D021901:DNA, Intergenic; D029702:Schizosaccharomyces pombe Proteins; D034501:Telomere-Binding Proteins; C505433:Dhc1 protein, S pombe; D004398:Dyneins