Fig. 5: Three-color 3D imaging of the synaptonemal complex in C. elegans.

Ratiometric three color 3D astigmatism imaging of the synaptonemal complex components HTP-3, HIM-3 and the N-terminus of SYP-5. a Three channel maximum intensity projection image of a whole mount C. elegans gonad showing the synaptonemal complex components HTP-3, HIM-3, and SYP-5. To create the image of the whole gonad, individual tiles were stitched using the Grid/Collection stitching Fiji plugin⁴⁵. b Top view of the bottom-most section of meiotic nuclei, with rendered SMLM localizations of the synaptonemal complex components colored by their z coordinate (z range −400 to 400 nm). c Cartoon showing relative positioning of the target proteins within the structure of the synaptonemal complex (based on previous research^31,32,33). d, e Zoomed-in image of the regions indicated in (b). f, g Top-view and side-view images of the synaptonemal complex stretches indicated in (e). h, i Histograms of localization counts along the 300 nm wide ROIs, as indicated in (d, e). Double Gaussian fits for localization distributions of individual proteins resulted in the following distances: HTP-3: 124 nm, HIM-3: 114 nm, SYP-5: 37 nm (h) and HTP-3: 157 nm, HIM-3: 130 nm, SYP-5: 0 nm (i). Representative results are shown from 2 experiments. Scale bars 10 μm (a), 1 μm (a inset, b, d–g).