PT  - JOURNAL ARTICLE
AU  - Fabian U. Zwettler
AU  - Marie-Christin Spindler
AU  - Sebastian Reinhard
AU  - Teresa Klein
AU  - Andreas Kurz
AU  - Markus Sauer
AU  - Ricardo Benavente
TI  - Tracking down the molecular architecture of the synaptonemal complex by expansion microscopy
AID  - 10.1101/821298
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 821298
4099  - http://biorxiv.org/content/early/2019/10/29/821298.short
4100  - http://biorxiv.org/content/early/2019/10/29/821298.full
AB  - 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 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 expansion factor determination. 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.