Fig. 2. Xrx1 inhibits neurogenesis. The effects of Xrx1 overexpression on (A) X-ngnr-1 (stage 12), (B,D,E) X-Delta-1 (stage 13), (C) N-tubulin (stage 16), (F) Sox2 (stage 13) and (G) XBF-1 (stage 13) are shown. (D,E) Transverse sections at the level of the anterior (D) and posterior (E) neural plate. The black arrowhead indicates the anterior expression domain of X-Delta-1, while the white arrowhead indicates the repression of the corresponding domain in the injected side. (H) Stage 16 embryo injected with 150 pg of XBF-1 RNA showing suppression of endogenous N-tubulin (white arrowheads) as well as ectopic N-tubulin activation at the border of the injected area (arrow). A-C,F,G,H Frontodorsal views. (I,K) Stage 16 embryos co-injected with either X-ngnr-1 and lacZ (I) or X-ngnr-1, Xrx1 and lacZ (K); lateral views, anterior towards the left. (J,L) Animal caps co-injected with either X-ngnr-1 and lacZ (J) or X-ngnr-1 and Xrx1 (L) analyzed at stage 16. Both in whole embryos and in animal caps Xrx1 inhibits N-tubulin expression induced by X-ngnr-1. Red staining represents expression of co-injected lacZ lineage tracer.