Fig. 4

Fig. 4 Expression pattern of cyp26d1 mRNA during pharyngula period of zebrafish. (A, C, E, G, I, K, M) lateral view, anterior left, dorsal top; (B, D, F, H, J, L, N) flatmount of anterior part of embryo, anterior top. (A, B) At 25 hpf, cyp26d1 gene is expressed in telencephalon, boundary between telencephalon and diencephalons, midbrain, dorsal part of hindbrain, pharyngeal arches (A) and otic vesicles (B). (C–F) The expression pattern of 25 hpf is maintained from 28 hpf through 31 hpf with high expression levels. Additionally, cyp26d1 is also expressed in the neural retina of eyes during 28–31 hpf (D, F). (G, H) At 35 hpf, the expression of cyp26d1 is mainly restricted to a dorsal part of telencephalon, otic vesicles, pharyngeal arches 2–7 and pectoral fins. At this stage, the expression in neural retina disappears except for a weak presence in lens. (I–L) With development, the expression level in telencephalon and otic vesicles is reduced and the expression at eyes, pharyngeal arches, and pectoral fins is hardly detectable from 42 hpf through 48 hpf. (M, N) Schematic diagrams summarizing the expression domains of the three cyp26 genes (cyp26a1, cyp26b1, and cyp26d1) in embryos at 24 hpf. Blue areas show the expression regions of cyp26a1, green ones mark the expression regions of cyp26b1, red ones show the expression regions of cyp26d1, yellow ones mark the regions where cyp26b1 and cyp26d1 are co-expressed and gray ones are the regions where cyp26a1, cyp26b1, and cyp26d1 are co-expressed. c, Cerebellum; d, diencephalon; ey, eye; h, hindbrain; m, midbrain; mh, midbrain–hindbrain boundary; nc, notochord; ot, otic vesicle; r, rhombomere; pa, pharyngeal arch; t, telencephalon; d, diencephalon.