XB-IMG-131763
Xenbase Image ID: 131763
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FIG. 2. Notch signaling regulates endogenous ligand expression. The expression of Delta-1 and Serrate-1 was examined in embryos injected with
mRNAs encoding either GR-Su(H)DBM (dominant negative) or GR-Su(H)VP16 (activated) into one ventrovegetal blastomere at the eight-cell stage.
As a lineage tracer, mRNA encoding b-galactosidase was co-injected and visualized using the substrate magenta-gal. At stages 19–20 constructs
were induced via the addition of the glucocorticoid dexamethasone to the injected embryos. Embryos were cultured until fixation at the desired
stage and examined by whole-mount in situ hybridization. (A) Lateral views of Delta-1 or Serrate-1 expression on the uninjected side of an embryo
(a, c) compared to the GR-Su(H)VP16-injected side (b, d). Note the decrease of Delta-1 expression on the injected side of the embryo when the Notch
pathway is activated in the region of the developing pronephros [black arrow in (b) marks the position of normal Delta-1 expression]. In contrast,
the expression of Serrate-1 is substantially increased on the GR-Su(H)VP16-injected side of the embryo [yellow arrow in (d) indicates region where
Serrate-1 expression is increased in the tubule anlage; red arrow in (d) identifies the expansion of Serrate-1 expression into a more posterior region
of the pronephros that normally forms the pronephric duct]. (B) The top two images show lateral views of Delta-1 expression on the uninjected (a)
and the GR-Su(H)DBM-injected (b) sides of an embryo. Note that Delta-1 expression is elevated on the injected side [black arrow in (b)], whereas
Serrate-1 expression is diminished [black arrow in (d) indicates the normal position of Serrate-1 expression]. Image published in: McLaughlin KA et al. (2000) Copyright © 2000. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View |