Fig. 6

Fig. 6 Inductive properties of Znr2/Sqt and Znr1/Cyc. (A) Animal caps from Xenopus embryos injected with znr2/sqt or znr1/cyc RNA were assayed at stage 10.5 (gastrula) for expression of Cerberus, gsc, noggin, and Xbra. Znr2 induced Cer and Xbra at all doses and gsc and noggin at relatively high doses. In contrast, Znr1/Cyc only induced Xbra. (B) Similarly treated animal caps were tested at stage 25 (neurula) for expression of Krox20, N-CAM, XlHbox6/hoxb9, and muscle-specific actin. Znr1/Cyc induced Krox-20 and N-CAM at high doses and XlHbox6/hoxb9 and ms-actin at all doses. In contrast, Znr2 did not induce Krox-20 or N-CAM. XlHbox6/hoxb9 transcript levels decline with increasing znr2 dose. Znr2 induced ms-actin at all doses. (C) Animal caps treated as in B were assayed for expression of cytokeratin, N-CAM, and ms-actin. Cytokeratin levels decline with increasing znr2/sqt dose, but remain constant at all znr1/cyc doses. As in B, N-CAM was induced by high doses of znr1/cyc (the ms-actin expression profile was also reproduced; not shown). The constitutively expressed fibroblast growth factor receptor (FGFR) was used as a loading control. WE, RNA from whole embryos; U, RNA from uninjected animal caps; _RT, no reverse transcriptase control.