Fig. 4

Ubiquitination of mitochondrial membranes at later stages. a-c Pla2g6-KO mouse (15 w); d, e Pla2g6-KO mouse (1 year); f-i Pla2g6-KO mouse (2 years); a, b, g anterior part of the spinal cord; c-f anterior root; h, i posterior part of the spinal cord; a, c immunohistochemistry for ubiquitin; b, d, f immunohistochemistry for ubiquitin plus LFB staining; e, g double immunohistochemistry for PαSyn (brown) and ubiquitin (blue); h, i double immunohistochemistry for ubiquitin (brown) and TOM20 (blue); Scale bars represent 80 μm in (a), 20 μm in (b-g) and 10 μm in (h, i). a At the pre-clinical stage, there is almost no expression of ubiquitin. b The anterior horn cell (arrow), filled with small granules, is negative for ubiquitin. c In the anterior root, no ubiquitin-positive axon can be observed. d At the early symptomatic stage, ubiquitin-positive axons (arrows) with LFB-positive (blue) myelin are seen in the anterior root. e The distribution of small PαSyn-positive granules (brown, arrows) and ubiquitin (blue) are different. f Ubiquitin-positive axons (arrows) are shown. Most of the myelinated fibers have become atrophic. g The distribution of small PαSyn-positive granules (brown) and ubiquitin (blue) differs. h In the center of a large spheroid, TOM20-positive (blue) granules are ubiquitin-positive (brown, arrow). i In the markedly ubiquitinated spheroid (brown), the expression of TOM20 (blue) is still observed