Fig. 1: FIB-SEM imaging and segmentation of epididymal epithelial cells.
a Representative XY slice of the IS, caput, corpus and cauda epididymis. The delineated area in orange is the IOR. Lu luminal part. Scale bar: 10 μm. b Three-dimensional reconstruction of FIB-SEM images derived from the 56 d caput epididymis. The dimensions of the volume are indicated. Scale bar: 5 μm. c Reconstruction of adjacent PCs (gray and Tiffany blue) and IORs (orange) in the IS, caput, corpus and cauda epididymis. Scale bar: 3 μm. d FIB-SEM image of a mouse epididymis fixed with 2.5% GA with osmium impregnation (OTO) showing the presence of the IOR. Scale bar: 2 μm. e TEM image of the caput epididymis after high-pressure freezing (HPF) showing the presence of the IOR. Scale bar: 1 μm. f Representative image of the membrane thickness comparison for the IOR and the cell membrane. Orange arrowhead, IOR membrane (MIOR, orange circle); green arrowhead, single-cell membrane (sM, green circle); yellow arrowhead, double-cell membrane (dM, yellow circle); blue arrowhead, mitochondrial membrane (mM, blue circle). Scale bar: 1 μm. g Corresponding statistical analysis of membrane thickness (n = 5 images from 3 mice for dM and mM; n = 6 images from 3 mice for sM and MIOR). One-way ANOVA followed by Tukey’s multiple comparisons test. ****p < 0.0001. Data are presented as mean value ± SEM. h TEM images of PC junctions showing that desmosome structures were distributed at both ends of the IORs. Yellow arrowhead, desmosome; blue arrowhead, tight junction. Scale bars from left to right: 1 μm, 100 nm.
