Xenbase Image ID: 130815

Fig. 3. BMP-3b and BMP-3 have apparently different dorsalizing activities in Xenopus embryos. (A–C) Xenopus embryos injected with BMP-3b or BMP-3 mRNA. Overexpression of BMP-3b led to ectopic head formation, whereas BMP-3 generated aberrant tail formation. Synthetic mRNAs (1 ng each) encoding xBMP-3b (A), xBMP-3 (B), or -galactosidase ( -gal; C) were injected into marginal zone of two ventral blastomeres at the four cell stage. (D–G) Differentiation of ventral marginal zone explants (VMZs) injected with BMP-3b or BMP-3. Typical explants are shown in circles. (D) VMZs injected with rBMP-3b RNA generated head-like structures, consisting of an eye and cement glands (68%, n 15). (E) VMZs injected with rBMP-3 elongated and formed melanocytes (93%, n 15). (F) Control VMZs developed cylindrical structures. (G) These VMZs were harvested at stage 41 and scored by RT-PCR. Injection of BMP-3b and BMP-3 caused expression of dorsal markers (cardiac actin and NCAM), and repression of a ventral marker ( globin). BMP-3b also elevated anterior tissue markers such as cement gland (xAG1), lens ( B1-crystallin), and retina (rhodopsin). EF1 is an internal loading control. Emb RT and RT are controls for cDNA synthesis and for genomic DNA contamination, respectively. (H) Analysis of early markers in embryos coinjected with -gal (100 pg), and either BMP-3b or BMP-3 (1 ng). Light blue staining represents area injected with BMP-3b (left) or BMP-3 (center). Brown staining represents expression of Otx2 (top panel), and Xwnt-8 (middle panel), and cerberus (bottom panel). All panels are vegetal views of embryos with dorsal aspect top. Injection of BMP-3b mRNA triggered ectopic Otx2 expression (top left), whereas injection of BMP-3b and BMP-3 reduced endogenous Xwnt8 expression (middle). BMP-3b did not induce cerberus expression, indicating that BMP-3b is involved in head formation independently of, or downstream from, cerberus. Image published in: Hino J et al. (2003) Copyright © 2003. Image reproduced with permission of the Publisher, Elsevier B. V. Gene Synonyms Species Stage(s) Tissue cer1.S cer, cer-1, Cerberus, dand4, LOC108713989, tCerberus, xcer, xcer-1, xcer1 X. laevis Throughout NF stage 11 marginal zone wnt8a.L wnt-8, wnt8, Xwnt-8, Xwnt8 X. laevis Throughout NF stage 11 marginal zone ventral marginal zone ventro-lateral marginal zone dorso-lateral marginal zone otx2.S otx-2, otx2-a, otx2-b, otxA, Xotx-2, Xotx2 X. laevis Throughout NF stage 11 dorsal marginal zone Image source: Published Larger Image Printer Friendly View

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