Polysome clustering by RSC and MMD reveals three recurrent classes. (a) Galleries of LMW, MMW, and HMW polysomes before classification. For each sample under consideration, manual object selection was used to generate galleries of images. We aligned rotationally and translationally 544 objects for the LMW sample, 567 objects for the MMW sample, and 700 objects for the HMW sample. Bars, 100 nm. (b) To identify the most populated classes of polysomes according to their rotational symmetry, the frequency of polysome classes in the SOM (4 rows, 12 columns) was obtained. Three classes appeared to be the most frequent among 674 HMW polysomes (for LMW and HMW refer to Fig. S2). (c) Heat map displaying the top scoring inter-class differences based on the MMD test. The largest differences (thicker stripes) are found between classes 1-1 and 1-12 and between 1-1 and 4-12 (corresponding to the most frequent classes in b). Classes 1-12 and 4-12 show a slightly lower difference. (d) Image classification in b sorted out images into clusters characterized by similar rotational symmetry. Each set of images corresponding to the three most populated classes (i.e., 1-1, 1-12, and 4-12, where the first number refers to the row and the second to the column position in the SOM) was used to obtain the characteristic mean rotational power spectra (mean ± SEM is displayed).