XB-IMG-131711
Xenbase Image ID: 131711
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Fig. 8. A repressor form of Brat, Brat-EnR, inhibits expression of
dorsal and ventral mesodermal markers. (A) Schematic diagram of
wild-type Brat (upper) and a chimera of the N terminus of Brat and
the Drosophila engrailed repressor domain, Brat-EnR (lower). The Tbox
is red, while the engrailed repressor domain is black.
(B) Diagram illustrating the experimental design. 2 ng Brat-EnR and
0.5 ng LacZ mRNA was injected into the marginal zone of both
blastomeres along the first cleavage plane at the 2-cell stage. Albino
embryos were used in which dorsal-ventral differences are not
apparent and therefore the site of injection is randomized with respect
to the dorsal or ventral side. (C,F) Wild-type whole-mount expression
patterns of Xbra and gsc. (D,G) Vegetal view of marker expression in
embryos injected with Brat-EnR. (E,H) Animal view of the same
embryos in D,G to show b-gal staining in the region coinjected with
Brat-EnR and Lac Z mRNA. Note that the expression of gsc and Xbra
is absent on the side expressing Brat-EnR. Xlim expression was also
absent in these embryos (data not shown). Since the site of injection
along the dorsal-ventral axis was randomized, gsc expression was
present opposite the b-gal stain in 50% of the embryos (n=30), as
expected. Xbra expression, on the contrary, was always eliminated in
the injected cells, whether injected dorsally or ventrally. Image published in: Horb ME and Thomsen GH (1997) Copyright © 1997. Image reproduced with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License. Larger Image Printer Friendly View |