Fig. 4

Genetic Dissection of the Zebrafish Chk1-Suppressed Apoptotic Pathway

(A) Quantified AO labeling in spinal cords of 12.5 Gy-exposed p53^e7/e7;chk1^MO embryos injected with H₂O (bar on the far left) or the indicated MOs (x axis). AO staining was quantified in e8 embryos per MO with a total of ≥100 embryos scored. All data are means ± SEM ^*** p < 0.0001 (two-tailed Student's t test).

(B) Fluorescent images of representative embryos from the experiments shown in (A).

(C) At left, RT-PCR of casp2 transcripts from embryos either injected or not injected with casp2 MO. At right, schematics of caspase-2 protein variants (top, wild-type protein; bottom, predicted protein translated from exon 4-deleted transcripts).

(D) Fluorescent images of embryos of the indicated genotypes with or without IR (12.5 Gy at 18 hpf), chk1 MO, or bcl-xl mRNA. Numbers in brackets refer to the corresponding bars in (E).

(E) Quantified AO responses (n ≥ 8) for embryos of indicated genotypes +/- bcl-xl mRNA. Gray bars, p53^+/+ background; black bars, p53^e7/e7;chk1^MO background. Numbers in brackets refer to the representative-embryo images in (D). Data are means ± SEM.