Fig. 1

Developmental mRNA expression pattern of the zebrafish cdx1b gene. cdx1b mRNA was detected in one-cell zygote (A), cleavage (B), blastula (D), shield (E,F), 80% epiboly (H-J), 1-2s (L,M), 18s (O-Q), 20 hpf (R-T), 28 hpf (V), 36 hpf (W), 48 hpf (X), 72 hpf (Y) and 96 hpf (Z) stages. (C,G,K,N,U) Embryos hybridized with the sense RNA probe. Double-labeled in situ hybridization showed the expression of cdx1b compared with either rx1, myoD (O,P) or shh (Q). The two lines in R show different boundaries of a 20 hpf embryo viewed at higher magnification in S and T. (a) Cryostat transverse section along the plane of the line shown in Z. (b) Semiquantitative RT-PCR revealed cdx1b expression levels in embryos from different developmental stages. a, anus; d, diencephalon; i, intestine; mb, midbrain; n, notochord; pp, prechordal plate; r, retina; s, somite. Scale bars: 100 μm.