Fig. 4. The expression of a ganglionic eminence-specific late marker gene in vivo and in neural stem cell colonies. (A) A coronal slice (400 µm thick) of E14.5 zfdlx4/dlx6lacZ transgenic mice brain was subject to X-gal staining, and showed robust transgene expression in subventricular zone and mantle zone, but not in ventricular zone, of the ganglionic eminence. Bar, 1.0 mm. (B) The expression of the endogenous Dlx5 gene was determined using RT-PCR. RNA was isolated from E14.5 primary neural stem cell colonies derived from cortical (CTX), medial ganglionic eminence (MGE), midbrain/rostral hindbrain (MB/rHB) or caudal hindbrain (cHB) germinal zone dissections, and generated after 7 days in culture. Positive amplification of 438 bp bands was demonstrated in the neural stem cell colonies from CTX and MGE, as well as in the corresponding primary tissues.