Fig. 3. Gli1, Gli2 and Gli3 are required for ectopic neurogenesis by activated neurogenic pathways. (Left panels) N-tubulin expression (purple) on stage 14-15 embryos co-injected (inj.) with Ngn1, NeuroD or Delta1^Stu and MO-C or MO-3, as indicated. Arrows indicate ectopic neuronal differentiation caused by Ngn1, NeuroD or Delta1^Stu. Panels show dorsal views and the ß-gal injection tracer is in red/pink for Delta1^Stu+MO-3. (Right panel) Lateral views of injected embryos at stage 13 showing the ß-gal injection tracer in light blue. Ectopic neurogenesis as determined by N-tubulin expression (purple, arrow) is only detected after injection of 1ng Ngn1a RNA plus MO-C, but not after co-injection of Ngn1a plus MO-1 or MO-2. Dorsal side is upwards, anterior towards the right.