A) Transmission electron micrograph of the initial segment region of the mouse epididymis showing particulate material within the lumen. SP, spermatozoon. Arrows, extracellular vesicles. Micrograph kindly provided by A. Parent and L. Hermo, McGill University, Montreal, Quebec Canada. Reprinted from (Cornwall et al., 2011). Bar, 0.5 μm. B) Indirect immunofluorescence analysis of the initial segment epididymal lumen using the anti-oligomeric amyloid antibody (A11) (green fluorescence). DAPI, blue fluorescence, indicates staining of epithelial cell nuclei. Bar, 20 μm. C) Thioflavin S staining of amyloid matrix isolated from the mouse initial segment; and D) cauda epididymis. Bar, 5 μm. E) X-ray diffraction of epididymal amyloid matrix isolated from the initial segment region of the epididymis. Reprinted from (Whelly et al., 2012).