XB-IMG-74864
Xenbase Image ID: 74864
|
||||||||||
|
Fig. 8. Neural induction requires the interplay of BMP, FGF and Wnt signals. (A) (i) Schematic of an animal cap assay. (ii) In situ hybridization examining Sox3 expression in animal caps injected as indicated and cultured to Stage 15. Sox3 expression is induced by BMP attenuation (Noggin expressing caps) but not by β-cateninδXTcf3. β-CateninδXTcf3 inhibits Noggin-mediated Sox3 expression when coexpressed. (B) β-CateninδXTcf3 inhibits Sox3 expression cell autonomously. Embryos were injected with mRNA encoding Noggin in both cells at the two-cell stage (iii) and subsequently at the four-cell stage a single blastomere was injected with β-gal alone (i) or β-gal plus β-cateninδXTcf3 (ii, iii). Note that cells expressing lineage tracer and β-cateninδXTcf3 do not also express Sox3. (iii) Magnified view of upper explant pictured in ii. (C) Embryos were injected into one cell at the two-cell stage with the indicated mRNA (noted in boxes above the embryo) and β-gal RNA. Embryos were harvested at stage 15 and probed for Sox3. Blocking FGF signals with a dominant inhibitory FGF receptor (dnFGFR) partially rescues expansion of the neural plate seen with δXTcf3 alone. Upregulation of BMP signaling with a constitutively active type 1 BMP receptor (caBMPR) also rescues the δXTcf3-mediated expansion of the neural plate and also decreases expression of Sox3 within the normal neural plate forming region. These findings indicate that the ability of δXTcf3 to induce ectopic neural tissue is dependent on the status of BMP and FGF signals. Arrows indicate injected side. Image published in: Heeg-Truesdell E and LaBonne C (2006) Copyright © 2006. Image reproduced with permission of the Publisher, Elsevier B. V.
Image source: Published Larger Image Printer Friendly View |