Fig 2. Suppressors of TDP-43 improve C. elegans motor function and reduce levels of toxic TDP-43.

(A) Motor function of animals doubly homozygous for the human mutant TDP-43 (M337V) transgene, TDP-43 tg, and loss-of-function mutations for the indicated suppressor genes was assessed. Dispersal velocity of developmentally staged L4 larvae was measured by calculating the radial distance traveled from a designated central starting point over time, N>200 for all strains tested. Significance was evaluated using one-way analysis of variance with Tukey’s multiple comparison test among strains tested. ***p<0.0001, *p<0.01 versus TDP-43 tg. non-Tg (N2) animals move 3.712 μm/ sec. (B) To assay the effects of loss-of-function mutations in suppressor genes present on the same chromosome as the TDP-43 tg transgene (Chr IV), a second human mutant TDP-43 (A315T) transgene was utilized on a different chromosome (Chr II), TDP-43 tg2. Animals doubly homozygous for the TDP-43 tg2 transgene and loss-of-function mutations for the TDP-43 suppressor genes indicated were assessed for motor function as above, N>200 for all strains tested. ***p<0.0001, **p<0.001, *p<0.01 versus TDP-43 tg2. (C-G) Measurement of levels of total and phosphorylated TDP-43 protein by immunoblot. Data shown are representative of triplicate independent experiments. Graphs plot relative total TDP-43 or phosphorylated TDP-43 signal normalized to tubulin protein levels from three or more independent replicate experiments. Significance was evaluated using Mann-Whitney test between strains tested. *p<0.05.