Faculty Opinions recommendation of Superresolution microscopy reveals the three-dimensional organization of meiotic chromosome axes in intact Caenorhabditis elegans tissue.

2017 ◽  
Author(s):  
Dean Dawson
Keyword(s):  
Caenorhabditis Elegans ◽  
Meiotic Chromosome ◽  
Three Dimensional ◽  
Superresolution Microscopy

scholarly journals Superresolution microscopy reveals the three-dimensional organization of meiotic chromosome axes in intact Caenorhabditis elegans tissue

2017 ◽  
Vol 114 (24) ◽  
pp. E4734-E4743 ◽  
Author(s):  
Simone Köhler ◽  
Michal Wojcik ◽  
Ke Xu ◽  
Abby F. Dernburg
Keyword(s):  
Caenorhabditis Elegans ◽  
Fluorescent Protein ◽  
Germ Line ◽  
Meiotic Chromosome ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Molecular Organization ◽  
Superresolution Microscopy ◽  
Specific Proteins ◽  
Optical Reconstruction

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.

scholarly journals Identification of a meiosis-specific chromosome movement pattern induced by persistent DNA damage

2020 ◽  
Author(s):  
Daniel León-Periñán ◽  
Alfonso Fernández-Álvarez
Keyword(s):  
Dna Damage ◽  
Meiotic Prophase ◽  
Meiotic Chromosome ◽  
Three Dimensional ◽  
Model Organism ◽  
Movement Pattern ◽  
Time Lapse ◽  
Chromosome Movement ◽  
Nuclear Movement ◽  
Chromosome Associations

ABSTRACTAs one of the main events occurring during meiotic prophase, the dynamics of meiotic chromosome movement is not yet well understood. Currently, although it is well-established that chromosome movement takes an important role during meiotic recombination promoting the pairing between homologous chromosomes and avoiding excessive chromosome associations, it is mostly unclear whether those movements follow a particular fixed pattern, or are stochastically distributed. Using Schizosaccharomyces pombe as a model organism, which exhibits dramatic meiotic nuclear oscillations, we have developed a computationally automatized statistical analysis of three-dimensional time-lapse fluorescence information in order to characterize nuclear trajectories and morphological patterns during meiotic prophase. This approach allowed us to identify a patterned oscillatory microvariation during the meiotic nuclear motion. Additionally, we showed evidence suggesting that this unexpected oscillatory motif might be due to the detection of persistent DNA damage during the nuclear movement, supporting how the nucleus also regulates its oscillations. Our computationally automatized tool will be useful for the identification of new patterns of nuclear oscillations during gametogenesis.

scholarly journals Label-free three-dimensional imaging of Caenorhabditis elegans with visible optical coherence microscopy

PLoS ONE ◽  
2017 ◽  
Vol 12 (7) ◽  
pp. e0181676 ◽  
Author(s):  
Séverine Coquoz ◽  
Paul J. Marchand ◽  
Arno Bouwens ◽  
Laurent Mouchiroud ◽  
Vincenzo Sorrentino ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Three Dimensional ◽  
Optical Coherence ◽  
Label Free ◽  
Optical Coherence Microscopy ◽  
Three Dimensional Imaging

scholarly journals Three-dimensional Ultrastructure of Saccharomyces cerevisiae Meiotic Spindles

2005 ◽  
Vol 16 (3) ◽  
pp. 1178-1188 ◽  
Author(s):  
Mark Winey ◽  
Garry P. Morgan ◽  
Paul D. Straight ◽  
Thomas H. Giddings ◽  
David N. Mastronarde
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Meiotic Chromosome ◽  
Three Dimensional ◽  
Structural Basis ◽  
Mitotic Spindles ◽  
Yeast Saccharomyces Cerevisiae ◽  
Homologous Chromosomes ◽  
Sister Chromatids ◽  
Single Nucleus ◽  
Meiotic Spindles

Meiotic chromosome segregation leads to the production of haploid germ cells. During meiosis I (MI), the paired homologous chromosomes are separated. Meiosis II (MII) segregation leads to the separation of paired sister chromatids. In the budding yeast Saccharomyces cerevisiae, both of these divisions take place in a single nucleus, giving rise to the four-spored ascus. We have modeled the microtubules in 20 MI and 15 MII spindles by using reconstruction from electron micrographs of serially sectioned meiotic cells. Meiotic spindles contain more microtubules than their mitotic counterparts, with the highest number in MI spindles. It is possible to differentiate between MI versus MII spindles based on microtubule numbers and organization. Similar to mitotic spindles, kinetochores in either MI or MII are attached by a single microtubule. The models indicate that the kinetochores of paired homologous chromosomes in MI or sister chromatids in MII are separated at metaphase, similar to mitotic cells. Examination of both MI and MII spindles reveals that anaphase A likely occurs in addition to anaphase B and that these movements are concurrent. This analysis offers a structural basis for considering meiotic segregation in yeast and for the analysis of mutants defective in this process.

scholarly journals Crossing over is coupled to late meiotic prophase bivalent differentiation through asymmetric disassembly of the SC

2005 ◽  
Vol 168 (5) ◽  
pp. 683-689 ◽  
Author(s):  
Kentaro Nabeshima ◽  
Anne M. Villeneuve ◽  
Monica P. Colaiácovo
Keyword(s):  
Caenorhabditis Elegans ◽  
Symmetry Breaking ◽  
Synaptonemal Complex ◽  
Central Region ◽  
Meiotic Prophase ◽  
Homologous Chromosome ◽  
Meiotic Chromosome ◽  
Crossing Over ◽  
Γ Irradiation ◽  
Irradiation Treatment

Homologous chromosome pairs (bivalents) undergo restructuring during meiotic prophase to convert a configuration that promotes crossover recombination into one that promotes bipolar spindle attachment and localized cohesion loss. We have imaged remodeling of meiotic chromosome structures after pachytene exit in Caenorhabditis elegans. Chromosome shortening during diplonema is accompanied by coiling of chromosome axes and highly asymmetric departure of synaptonemal complex (SC) central region proteins SYP-1 and SYP-2, which diminish over most of the length of each desynapsing bivalent while becoming concentrated on axis segments distal to the single emerging chiasma. This and other manifestations of asymmetry along chromosomes are lost in synapsis-proficient crossover-defective mutants, which often retain SYP-1,2 along the full lengths of coiled diplotene axes. Moreover, a γ-irradiation treatment that restores crossovers in the spo-11 mutant also restores asymmetry of SYP-1 localization. We propose that crossovers or crossover precursors serve as symmetry-breaking events that promote differentiation of subregions of the bivalent by triggering asymmetric disassembly of the SC.

DNA Origami Nanopillars as Standards for Three-Dimensional Superresolution Microscopy

Nano Letters ◽  
2013 ◽  
Vol 13 (2) ◽  
pp. 781-785 ◽  
Author(s):  
Jürgen J. Schmied ◽  
Carsten Forthmann ◽  
Enrico Pibiri ◽  
Birka Lalkens ◽  
Philipp Nickels ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dna Origami ◽  
Superresolution Microscopy

scholarly journals Obtaining 3D Super-resolution Information from 2D Super-resolution Images through a 2D-to-3D Transformation Algorithm

2017 ◽  
Author(s):  
Andrew Ruba ◽  
Wangxi Luo ◽  
Joseph Kelich ◽  
Weidong Yang
Keyword(s):  
Single Molecule ◽  
Rotational Symmetry ◽  
Three Dimensional ◽  
Super Resolution ◽  
Live Cells ◽  
Limited Information ◽  
Spatiotemporal Resolution ◽  
Superresolution Microscopy ◽  
Localization Analysis ◽  
Probability Information

AbstractCurrently, it is highly desirable but still challenging to obtain three-dimensional (3D) superresolution information of structures in fixed specimens as well as dynamic processes in live cells with a high spatiotemporal resolution. Here we introduce an approach, without using 3D superresolution microscopy or real-time 3D particle tracking, to achieve 3D sub-diffraction-limited information with a spatial resolution of ≤ 1 nm. This is a post-localization analysis that transforms 2D super-resolution images or 2D single-molecule localization distributions into their corresponding 3D spatial probability information. The method has been successfully applied to obtain structural and functional information for 25-300 nm sub-cellular organelles that have rotational symmetry. In this article, we will provide a comprehensive analysis of this method by using experimental data and computational simulations.

scholarly journals Particle localization using local gradients and its application to nanometer stabilization of a microscope

2021 ◽  
Author(s):  
Anatolii V. Kashchuk ◽  
Oleksandr Perederiy ◽  
Chiara Caldini ◽  
Lucia Gardini ◽  
Francesco Saverio Pavone ◽  
...  
Keyword(s):  
Single Molecule ◽  
Three Dimensional ◽  
Universal Method ◽  
Superresolution Microscopy ◽  
Accurate Localization ◽  
Micro Particles ◽  
Localization Algorithms ◽  
Gradient Calculation ◽  
Particle Localization ◽  
Local Gradient

Accurate localization of single particles plays an increasingly important role in a range of biological techniques, including single molecule tracking and localization-based superresolution microscopy. Such techniques require fast and accurate particle localization algorithms as well as nanometer-scale stability of the microscope. Here, we present a universal method for three-dimensional localization of single labeled and unlabeled particles based on local gradient calculation of microscopy images. The method outperforms current techniques in high noise conditions, and it is capable of nanometer accuracy localization of nano- and micro-particles with sub-ms calculation time. By localizing a fixed particle as fiducial mark and running a feedback loop, we demonstrate its applicability for active drift correction in sensitive nanomechanical measurements such as optical trapping and superresolution imaging. A multiplatform open software package comprising a set of tools for local gradient calculation in brightfield and fluorescence microscopy is shared to the scientific community.

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