Figure 7
Ubiquitin immunolabeling in amyotrophic lateral sclerosis-linked mutant human superoxide dismutase transgene (SOD1 G93A ) and wild-type (WT) mice. Ubiquitin (red, A-F) was localized to the nucleus in WT (A,C,E) and SOD1G93A (B,D,F) motor neurons (SMI32, green, A-F). In SOD1G93A mice lumbar spinal cord, intracellular ubiquitin-positive inclusions were present from 6 weeks of age (arrow, B) onwards. SOD1G93A mice also showed extra-neuronal ubiquitin-positive inclusions from 10 weeks of age (D), with numerous ubiquitin aggregates by 25 weeks of age (F). Additionally, vacuolated lumbar motor neurons were observed from 10 weeks of age (arrow, D). Intracellular ubiquitinated aggregates were observed at 10 weeks of age in cervical motor neurons (G, arrow); at 14 weeks of age, intracellular (H, arrow) and extracellular (H, arrowhead) ubiquitin-positive aggregates were present in the SOD1G93A cervical ventral horn, and increased in number with time (I, 22 weeks of age). Scale bar 12 μm in A-F, 20 μm in G-I.