Spatial expression of mRNAs of CYP subtypes. Zebrafish embryos were exposed to 100 µM rifampicin (Rifam; (F,L,P)), 100 µM phenobarbital (Pheno; (I,M)), or 1.0 ppb TCDD (H,O) and 0.1% dimethyl sulfoxide (DMSO) as vehicle control (DMSO; (E,G,J,K,N)). (A,B) are published images of elov1a, a marker of the primordial bladder ((A) at 2 days post-fertilization [dpf], (B) at 3 dpf) [37]. (C,D) are published images of foxa3, a marker of the primordial liver (black arrowheads) and intestine (black arrows) and bladder (asterisks) ((C) at 2 dpf, (D) at 3 dpf) [38]. Larval zebrafish (55 hpf) were used for whole-mount in situ hybridization with RNA probes for cyp2n13 (E,F), cyp2r1 (G–I), cyp2y3 (J–M), and cyp3a65 (N–P). Asterisks indicate possible bladder primordium (F) and white arrowheads and arrows indicate possible primordia of the liver and intestine, respectively (H–P). Scale bars in (E–P) indicate 200 µm. (A–D) are reproduced from previous reports ([37] for (A,B), and [38] for (C,D)).