XB-IMG-74956
Xenbase Image ID: 74956
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Fig8. HoxD1 expression is ablated by the misexpression of dominant negative receptors. Data is detailed in Table 1. Albino embryos were micro-injected with a mixture of B-galactosidase mRNA (as a tracer) and dominant negative mRNA in one blastomere of a 2-cell embryo as described under Materials and Methods (thyroid hormone receptor: c-erbA (Barattino et al. 1993); dominant negative activin receptor: XAR delta (Hemmati-Brivanlo et al 1992); dominant negative fibroblast growth factor receptor: XFD (Amaya et al 1991). Embryos were allowed to develop to late gastrula-early neurula stage (Stage 12.5-13) and expression of HoxD1 was examined by in situ hybridization as described above. The expression of the mesodermal marker Xbra was also examined as a control. Xbra is expressed around the blastopre and in the notochord. At the stage examined (stage 12.5-13) the notochord has just begun to extend, so that notochord staining is visible to varying degrees (Nieuwkoop and Faber 1967). lacZ staining (light blue) localizes the injected mRNA. this staining is punctate due to a nuclear localization signal linked to the lacZ protein. Failure to see overlap of lacZ stain and HoxD1 mRNA in the normal domain of HoxD1 expression indictates ablation of expression by the dominant negative receptor. (A) HoxD1 expression; CAT RNA injected, dorsal view. (B) HoxD1 expression: c-erbA RNA- injected, dorsolateral view. (C) Xbra expression: c-erbA RNA-injected, dorsolateral-view. (D) HoxD1 expression: XARdelta RNA-injected, dorsal view. (E) Xbra expression, XARdelta RNA injected. (F) HoxD1 expression: XFD RNA-injected, dorsal view. (G) Xbra expression: XFD RNA-injected. Anterior is to the right. D= dorsal midline; bp= blastopore. Image published in: Kolm PJ and Sive HL (1995) Copyright © 1995. Image reproduced with permission of the Publisher, Elsevier B. V.
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