Fig. 3

Figure 3. Accumulation and aggregation of Dendra-α-SYN. (A) Representative confocal images of the mosaic expression of Dendra-α-SYN in the spinal cord. Both Dendra-α-SYN-wt and A53T-expressing larvae showed bright puncta of Dendra signal along the axons (white arrowheads) in 3 d.p.f. fish. Images (i,ii) show puncta in axons in detail. Scale bar represents 150 µm. (B) Quantification of Dendra puncta seen in transverse sections across the head of 3 d.p.f larvae with pan-neuronal expression of Dendra-α-SYN-wt and A53T represented in Figure S3E. No changes were found in the number of puncta. Data represented as mean (red line) ± s.d. (N = minimum of 6 fish, ns p > 0.05) (C) Thioflavin-S staining of longitudinal sections through the brain of 3 d.p.f embryos with pan-neuronal expression of Dendra-α-SYN-wt and A53T. Positive staining was observed in α-SYN -wt and A53T fish in contrast to the absence of labelling in transgene-negative siblings or Dendra-tau-A152T expressors. Panels i-iv correspond to magnified images where arrowheads point to thioflavin-s positive structures. Scale bar represents 100 µm. (D–F) Representative confocal images from maximum projections of z-stacks of Dendra positive neurons in the spinal cord of mosaic Dendra-α-SYN-wt and A53T expressors at 22 h.p.f., showing the early presence of Dendra-α-SYN aggregates (white arrowheads in (D)), de novo formation of Dendra-α-SYN-A53T aggregates (red arrowhead in (E)), and the increase in size of aggregates within 3 h (31–34 h.p.f.) (yellow arrowheads in (F)). Scale bar represents 25 µm.