CLEM images of spherical aggregates in a [PSI⁺] cell. (A) Fluorescence (left) and EM (right) images of a Sup35NM-GFP aggregate in a [PSI⁺] cell. Cells expressing Sup35NM-GFP were fixed after fluorescence imaging (left), and the thin section containing the same spherical aggregate identified by the fluorescence microscopy was subjected to EM analysis (right). CW, cell wall; M, mitochondrion; N, nucleus; V, vacuole. (B) The area within the red box in A is magnified. (C) Fourier-filtered image (left) of the area within the yellow dashed box in B. The spherical aggregate of Sup35NM-GFP in B was processed, using the fast Fourier transform plug-in in ImageJ software. In the right panel, drawings are superimposed on the Fourier transform image indicating fibril-like structures (red lines).