Fig. 1

The expression domains of the ascl1a, dlx, and gad1b genes overlap in the forebrain of the embryonic zebrafish. Single z sections on triple fluorescent in situ hybridizations. (A) In the forebrain lateral view of a WT embryo, the dlx1a and ascl1a are co-expressed throughout the telencephalon and prethalamus at 24 hpf, while ascl1b is not co-expressed at this stage. (B) The dlx1a, dlx5a, and gad1b genes are co-expressed in the telencephalon, prethalamus, and hypothalamus at 24 hpf. (C) The dlx1a, dlx5a, and gad1b genes continue to be co-expressed in the telencephalon and prethalamus at 48 hpf. The gad1b expression is increased in the dorsal tip of the telencephalon (arrow). The plane of section for (D) is shown as a dotted line in C′′′. (D) Cross-section showing the co-expression of dlx1a, dlx5a, and gad1b in the prethalamus (arrow). The rostral thalamus (arrowhead) is positive for gad1b expression but not dlx1 or dlx5a. Tel=telencephalon, Pth=prethalamus, Hy=hypothalamus, rTh=rostral thalamus. Scale bar in A–D=100 μm and in E=40 μm.