title: Imposition of crossover interference through the nonrandom distribution of synapsis initiation complexes.
abstract: Meiotic crossovers (COs) are nonrandomly distributed along chromosomes such that two COs seldom occur close together, a phenomenon known as CO interference. We have used genetic and cytological methods to investigate interference mechanisms in budding yeast. Assembly of the synaptonemal complex (SC) initiates at a few sites along each chromosome, triggered by a complex of proteins (including Zip2 and Zip3) called the synapsis initiation complex (SIC). We found that SICs, like COs, display interference, supporting the hypothesis that COs occur at synapsis initiation sites. Unexpectedly, we found that SICs show interference in mutants in which CO interference is abolished; one explanation is that these same mutations eliminate the subset of COs that normally occur at SICs. Since SICs are assembled in advance of SC and they are properly positioned even in the absence of SC formation, these data clearly demonstrate an aspect of interference that is independent of synapsis.
authors.affiliation: Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Fung
authors.forename: Beth
authors.initials: B
authors.lastname: Rockmill
authors.forename: Michael
authors.initials: M
authors.lastname: Odell
authors.forename: G Shirleen
authors.initials: GS
authors.lastname: Roeder
mesh_terms: D002352:Carrier Proteins / Q000235:genetics; D002478:Cells, Cultured; D023902:Chromosome Pairing / Q000235:genetics*; D002875:Chromosomes / Q000235:genetics*; D046911:Macromolecular Substances; D008540:Meiosis / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D013573:Synaptonemal Complex / Q000235:genetics
chemical_list: D002352:Carrier Proteins; D046911:Macromolecular Substances