Fig. 4

(A to P) Zebrafish (27-month-old) were intraperitoneally injected with TPT (22.5 mg/kg) or DMSO (22.5 mg/kg) on two consecutive days for a final concentration of 45 mg/kg and monitored for 1.5 hours using a camera system 24 and 48 hours after the second injection. P values, two-tailed Student’s t test with Holm post hoc analysis for multiple comparisons. Total distance traveled (A and B), average speed (C and D), low speed count (E and F), low speed duration (G and H), medium speed count (I and J), medium speed duration (K and L), high speed count (M and N), and high speed duration (O and P) were quantified after the second injection. (Q) Tissues were dissected from 29-month-old fish and treated with 14 μM CPT for 2 hours and then examined for Top1-CC accumulation using CsCl fractionation and immunoblotting, as described in Materials and Methods. (R) Quantification of (Q); two biologically independent experiments for heart and gut and four for brain; for each independent repeat, either four hearts or four guts were pooled. One brain was used for each independent repeat; ±SEM. P values, two-tailed Student’s t test. n.s., not significant. *P < 0.05; **P < 0.01.