Fig. 4.

Characterization of C6 and C25. C6 and C25 are analogs (structures in Supplementary Fig. S1) with similar biological activity but different chemical stability. (A) Dosage curve of C6. The prime attenuation of heart failure is observed at 90% by 1 μM C6. (B) Dosage curve of C25. Although C25 is not as potent as C6, with the prime attenuation of heart failure at 80% by 10 μM, it is more stable than C6. (C–G) C25 toxicity. Embryos treated with 10 μM C25 show a slightly curvy tail phenotype. Similar to MEK-I, later treatment of C25 shows weaker toxicity, indicating that it targets the early developmental process. C25 does not cause albinism. (H) Time course experiment shows that the critical time window of C25 function is between 24 (80% attenuation) and 36 (40% attenuation or 50% efficacy) hpf. Paired t-test comparing 24 hpf and other time points showed P=0.12 (30 hpf), 0.074 (36 hpf), 0.016 (42 hpf), and 0.005 (48 hpf). The data presented are means±SEM of triplicate wells (n=3), and the dosage curve experiments were repeated at least thrice except for C6, which was done multiple times but not in triplicate.