MilliporeSigma
  • Tracking down the molecular architecture of the synaptonemal complex by expansion microscopy.

Tracking down the molecular architecture of the synaptonemal complex by expansion microscopy.

Nature communications (2020-06-28)
Fabian U Zwettler, Marie-Christin Spindler, Sebastian Reinhard, Teresa Klein, Andreas Kurz, Ricardo Benavente, Markus Sauer
ABSTRACT

The synaptonemal complex (SC) is a meiosis-specific nuclear multiprotein complex that is essential for proper synapsis, recombination and segregation of homologous chromosomes. We combined structured illumination microscopy (SIM) with different expansion microscopy (ExM) protocols including U-ExM, proExM, and magnified analysis of the proteome (MAP) to investigate the molecular organization of the SC. Comparison with structural data obtained by single-molecule localization microscopy of unexpanded SCs allowed us to investigate ultrastructure preservation of expanded SCs. For image analysis, we developed an automatic image processing software that enabled unbiased comparison of structural properties pre- and post-expansion. Here, MAP-SIM provided the best results and enabled reliable three-color super-resolution microscopy of the SCs of a whole set of chromosomes in a spermatocyte with 20-30 nm spatial resolution. Our data demonstrate that post-expansion labeling by MAP-SIM improves immunolabeling efficiency and allowed us thus to unravel previously hidden details of the molecular organization of SCs.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Agarose, BioReagent, for molecular biology, low EEO
Sigma-Aldrich
Ethylenediaminetetraacetic acid disodium salt dihydrate, 98.5-101.5%, BioUltra
Sigma-Aldrich
Cysteamine, ~95%
Sigma-Aldrich
Bovine Serum Albumin, lyophilized powder, ≥96% (agarose gel electrophoresis)
Sigma-Aldrich
Sodium chloride, BioXtra, ≥99.5% (AT)
Sigma-Aldrich
D-(+)-Glucose, ≥99.5% (GC)
Sigma-Aldrich
Trizma® base, BioPerformance Certified, meets EP, USP testing specifications, suitable for cell culture, ≥99.9% (titration)
Sigma-Aldrich
Formaldehyde solution, for molecular biology, 36.5-38% in H2O
Sigma-Aldrich
Sodium acrylate, 97%
Sigma-Aldrich
Potassium hydroxide, ≥85% KOH basis, pellets, white
Sigma-Aldrich
Guanidine hydrochloride, BioUltra, for molecular biology, ≥99.5% (AT)
Sigma-Aldrich
N,N′-Methylenebisacrylamide solution, suitable for electrophoresis, 2% in H2O
Sigma-Aldrich
Ammonium persulfate, for molecular biology, suitable for electrophoresis, ≥98%
Sigma-Aldrich
N,N,N′,N′-Tetramethylethylenediamine, BioReagent, for molecular biology, ≥99% (GC)
Sigma-Aldrich
Acrylamide solution, 40%, suitable for electrophoresis, sterile-filtered
Sigma-Aldrich
Sodium dodecyl sulfate, BioReagent, suitable for electrophoresis, for molecular biology, ≥98.5% (GC)
Sigma-Aldrich
Proteinase K from Tritirachium album, buffered aqueous glycerol solution, for molecular biology, ≥800 units/mL
Sigma-Aldrich
Poly-D-lysine hydrobromide, mol wt 70,000-150,000, lyophilized powder, γ-irradiated, BioReagent, suitable for cell culture
Sigma-Aldrich
Polyoxyethylene (20) sorbitan monolaurate solution, ampule, ~10% in H2O
Sigma-Aldrich
Phosphate buffered saline, 10× concentrate, BioPerformance Certified, suitable for cell culture