RRC ID 51402
著者 Köhler S, Wojcik M, Xu K, Dernburg AF.
タイトル Superresolution microscopy reveals the three-dimensional organization of meiotic chromosome axes in intact Caenorhabditis elegans tissue.
ジャーナル Proc Natl Acad Sci U S A
Abstract When cells enter meiosis, their chromosomes reorganize as linear arrays of chromatin loops anchored to a central axis. Meiotic chromosome axes form a platform for the assembly of the synaptonemal complex (SC) and play central roles in other meiotic processes, including homologous pairing, recombination, and chromosome segregation. However, little is known about the 3D organization of components within the axes, which include cohesin complexes and additional meiosis-specific proteins. Here, we investigate the molecular organization of meiotic chromosome axes in Caenorhabditis elegans through STORM (stochastic optical reconstruction microscopy) and PALM (photo-activated localization microscopy) superresolution imaging of intact germ-line tissue. By tagging one axis protein (HIM-3) with a photoconvertible fluorescent protein, we established a spatial reference for other components, which were localized using antibodies against epitope tags inserted by CRISPR/Cas9 genome editing. Using 3D averaging, we determined the position of all known components within synapsed chromosome axes to high spatial precision in three dimensions. We find that meiosis-specific HORMA domain proteins span a gap between cohesin complexes and the central region of the SC, consistent with their essential roles in SC assembly. Our data further suggest that the two different meiotic cohesin complexes are distinctly arranged within the axes: Although cohesin complexes containing the kleisin REC-8 protrude above and below the plane defined by the SC, complexes containing COH-3 or -4 kleisins form a central core, which may physically separate sister chromatids. This organization may help to explain the role of the chromosome axes in promoting interhomolog repair of meiotic double-strand breaks by inhibiting intersister repair.
巻・号 114(24)
ページ E4734-E4743
公開日 2017-6-13
DOI 10.1073/pnas.1702312114
PII 1702312114
PMID 28559338
PMC PMC5474826
MeSH Animals Animals, Genetically Modified Caenorhabditis elegans / genetics Caenorhabditis elegans / metabolism Caenorhabditis elegans / ultrastructure* Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism Cell Cycle Proteins / chemistry Cell Cycle Proteins / genetics Cell Cycle Proteins / metabolism Chromosomal Proteins, Non-Histone / chemistry Chromosomal Proteins, Non-Histone / metabolism Chromosome Pairing Chromosome Segregation Chromosomes / genetics Chromosomes / metabolism Chromosomes / ultrastructure* Imaging, Three-Dimensional Meiosis Microscopy / methods Models, Biological Recombinant Fusion Proteins / genetics Recombinant Fusion Proteins / metabolism Stochastic Processes
IF 9.412
引用数 19
リソース情報
線虫 tm3655