Xenbase Image ID: 79181

Fig. 8. Xbtg1 is a target of both Xbra and Pintallavis and its overexpression blocks gastrulation movements. (A) Construction of Pintallavis-EnR. The repressor domain of the Drosophila Engrailed protein was fused to the carboxy terminus of the DNA-binding domain of Pintallavis (amino acids 85–241). (B,C) Overexpression of Xbtg1 inhibits gastrulation movements. (B) Section of control stage 12 embryo. (C) Sibling embryo injected with 1 ng Xbtg1 RNA. Gastrulation movements are inhibited. Sections in (B,C) are stained by the Feulgen technique to visualize nuclei (purple) and with an antibody specific for phosphorylated histone H3 to reveal mitotic nuclei (brown). (D–O) Phenotypes of control embryos or embryos injected with Pintallavis-EnR or Xbtg1. Embryos were fixed at stage 35/36 and stained either with notochord-specific antibody MZ15 (E,F,I,J,M,N) or muscle-specific antibody 12/101 (G,K,O). Otic vesicles are indicated by arrowheads in (E,F). Embryos injected with Pintallavis-EnR or Xbtg1 frequently had enlarged notochords (compare (F), a control uninjected embryo, with (J), an embryo injected with Pintallavis-EnR, and (N), an embryo injected with Xbtg1; all three are dorsal views at the same magnification). (P–R) Suppression of Xbtg1 expression by Xbra-EnR and Pintallavis-EnR. A single cell of embryos at the 8- or 32-cell stage was injected with Xbra-EnR (P), Pintallavis-EnR (Q) or both (R), together with lineage tracer Fluorescein-dextran (red). The injected embryos were fixed at stage 10.5 and were hybridized with Xbtg1 probe (blue). Image published in: Saka Y et al. (2000) Copyright © 2000. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View

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