Fig. 3. A DNA fragment encompassing the zebrafishdlx4/dlx6 intergenic region directs expression oflacZ in transgenic mouse embryos with patterns that closely recapitulate endogenous Dlx5 andDlx6 expression in the forebrain. A–C,lacZ expression in the ventral thalamus (VT), basal telencephalon (BT), and olfactory placodes (OP) in E10 (A), E11 (B), and E12 (C) whole-mount mouse embryos.D, Coronal section of an E14.5 stage mouse embryo withlacZ expression in the lateral ganglionic eminence (LGE). Higher β-galactosidase activity is seen in the subventricular zone (SVZ) compared to the mantle (MZ). E, F,In situhybridizations with Dlx5 (E) andDlx6 (F) probes on coronal sections adjacent to that seen in D. Note that the relative patterns of Dlx5 expression in the SVZ and MZ more closely resemble that seen in transgenic animals (D) than do the relative patterns ofDlx6 expression. G–I, More caudal sections of the same embryonic brain. G, Expression of β-galactosidase in the caudal ganglionic eminence (CGE), preoptic area (POA), and ventral diencephalon. H, I,In situhybridizations with Dlx5 and Dlx6 probes, respectively, on sections adjacent to those seen in G. Embryos in A and B are from line 7679, and those in C–I are from line 1469.J–L, A 1.4 kb XhoI/EcoRI fragment from the zebrafish dlx4/dlx6 intergenic region directs expression of a transgene that recapitulates endogenousdlx expression in the forebrain of zebrafish embryos.J, Expression of GFP directed by the 1.4 kb I4/6 zebrafish fragment in a 36 hr embryo. The patterns are similar to the expression of the endogenous dlx4(K) and dlx6(L) genes. The domains I and II ofdlx expression correspond, by analogy, to the diencephalic (I) and telencephalic (II) domains of Dlx expression in the mouse.I, Domain I; II, domain II;AEP, anterior entopeduncular area; BT, basal telencephalon; Cx, cortex; Hy, hypothalamus; LV, lateral ventricle; OB, prospective olfactory bulb; Se, septum;SPV, supraoptic paraventricular area; VZ, ventricular zone.