title: Synaptonemal complex assembly in C. elegans is dispensable for loading strand-exchange proteins but critical for proper completion of recombination.
abstract: Here we probe the relationships between assembly of the synaptonemal complex (SC) and progression of recombination between homologous chromosomes during Caenorhabditis elegans meiosis. We identify SYP-2 as a structural component of the SC central region and show that central region assembly depends on proper morphogenesis of chromosome axes. We find that the SC central region is dispensable for initiation of recombination and for loading of DNA strand-exchange protein RAD-51, despite the fact that extensive RAD-51 loading normally occurs in the context of assembled SC. Further, persistence of RAD-51 foci and absence of crossover products in meiotic mutants suggests that SC central region components and recombination proteins MSH-4 and MSH-5 are required to promote conversion of resected double-strand breaks into stable post-strand exchange intermediates. Our data also suggest that early prophase barriers to utilization of sister chromatids as repair templates do not depend on central region assembly.
authors.affiliation: Department of Developmental Biology, Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Mónica P
authors.initials: MP
authors.lastname: Colaiácovo
authors.forename: Amy J
authors.initials: AJ
authors.lastname: MacQueen
authors.forename: Enrique
authors.initials: E
authors.lastname: Martinez-Perez
authors.forename: Kent
authors.initials: K
authors.lastname: McDonald
authors.forename: Adele
authors.initials: A
authors.lastname: Adamo
authors.forename: Adriana
authors.initials: A
authors.lastname: La Volpe
authors.forename: Anne M
authors.initials: AM
authors.lastname: Villeneuve
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D023902:Chromosome Pairing; D002875:Chromosomes / Q000378:metabolism; D003434:Crossing Over, Genetic; D004249:DNA Damage / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D004706:Endodeoxyribonucleases; D004950:Esterases / Q000378:metabolism; D007150:Immunohistochemistry; D007211:Indoles / Q000378:metabolism; D008540:Meiosis; D008969:Molecular Sequence Data; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000302:isolation & purification / Q000502:physiology*; D034741:RNA, Small Interfering / Q000378:metabolism; D051135:Rad51 Recombinase; D011995:Recombination, Genetic / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D016415:Sequence Alignment; D013573:Synaptonemal Complex / Q000378:metabolism* / Q000648:ultrastructure; D013997:Time Factors; D000099257:Meiotic Recombination Protein SPO11
chemical_list: D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D004706:Endodeoxyribonucleases; D004950:Esterases; D007211:Indoles; D009419:Nerve Tissue Proteins; D034741:RNA, Small Interfering; D051135:Rad51 Recombinase; D029701:Saccharomyces cerevisiae Proteins; D000099257:Meiotic Recombination Protein SPO11; C091158:MSH4 protein, S cerevisiae; C094801:MSH5 protein, S cerevisiae; C478060:SYP-2 protein, C elegans; C007293:DAPI; C495148:rad-51 protein, C elegans