Xenbase Image ID: 44917

Fig. 5. Time course of the ability of Otx2 and Xgbx2a to affect En2 expression. Embryos were injected unilaterally at the two-cell stage either with Xgbx2a/GR or Otx2/GR RNA, or with both in adjacent cells. The hormone-inducible proteins were activated either at stage 10.5 (A,C,E) or at stage 15 (B,D,F). In all instances LacZ mRNA was co-injected as a lineage tracer. (A) Embryo injected unilaterally with Xgbx2a/GR. Dexamethasone was added at stage 10.5. En2 expression was inhibited on the injected side. (B) Embryo injected similarly to (A), but activation by dexamethasone was at stage 15. The ability of Xgbx2a/GR to inhibit En2 is maintained at stage 15. (C) Embryo injected with Otx2/GR. Dexamethasone was added at stage 10.5. On the injected side, En2 expression was ectopically activated in posterior and lateral regions. (D) Embryo injected similarly to (C), but dexamethasone was added at stage 15. The ability of Otx2/GR to induce ectopic En2 expression was considerably diminished as compared to stage 10.5 activation. The ectopic expression (arrowhead) is restricted to a thin stripe along the midline. (E,F) Embryos injected with Otx2/GR into one cell and Xgbx2a/GR along with the lineage tracer into the adjacent cell. (E) Activation of the proteins at stage 10.5 causes inhibition of En2 expression at the MHB in both the Xgbx2a/GR- and Otx2/GR-injected sides and its posterior ectopic activation in the Otx2/GR-injected side. (F) Dexamethasone addition at stage 15. The MHB expression of En2 is inhibited by both constructs. Weak ectopic activation of En2 is seen along the dorsal midline (arrowheads). Image published in: Tour E et al. (2002) Copyright © 2002. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View

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