Supplemental Material for Sae-Lee et al., 2020
Figure S1. Representative images of degenerating HSN neurons. A-C, Degenerated HSN neurons had dim (arrow heads) or barely visible (dotted circle) cell bodies. D-G, Earlier evidence of HSN neuron degeneration was visible as blebbing of the cell body (arrows). H-I, Processes of degenerating HSN neurons also showed beading (H, arrows) that was not visible in healthy HSN neurons (I). Autofluorescence from intestine bright in panels H and I due to higher gain to visualize HSN axon. VC4 and VC5 neurons fluorescing out of focus in panels B-F.
Figure S2. APP::mCherry is expressed throughout the nervous system. A DIC and fluorescent photomicrographs at 40X along the length of the worm. A C-terminal mCherry tag shows APP expression. As expected, we found that APP expressed under a pan-neuronal promoter was seen throughout the entire nervous system including the nerve ring and along the ventral nerve cord in the absence (left) and presence (right) of exAPOE4. B Enlarged photomicrographs of the ventral nerve cord taken mid-body show that APP is expressed in a punctate pattern in the VCs both when APOE4 expression is absent (top) and present (bottom). C Enlarged photomicrographs show that APP is expressed in a punctate pattern in the HSNs.
Figure S3. APOE3 and APOE4 transgene levels. A, Semi-quantitative analysis of level of APOE transgene arrays in genomic DNA. Average band intensities of three independent genomic preparations from five worms/strain following PCR for human APOE presented as mean ± SEM. No significant differences were found when comparing levels for APOE3 vs APOE4 strains after correcting for multiple comparisons. B, Expression of APOE determined by RT-qPCR of mRNA isolated from 3 (integrated) or 9 (extrachromosomal) near-starved 6-cm plates of worms. DCt values reveal little difference in gene expression between strains. Values represent the mean ± SE of two independent biological replicates with three technical replicates each. Data is represented as gene expression relative to the reference control gene tba-1.
Table S1. List of strains used throughout our study arranged by Figure.