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Figure 7 | Neural Development

Figure 7

From: Dorsoventral patterning of the Xenopus eye involves differential temporal changes in the response of optic stalk and retinal progenitors to Hh signalling

Figure 7

Proposed model of the stage dependent effects of Hh signalling in the DV patterning of the Xenopus eye. (A) During gastrula/neurula stages of development, Hh signalling controls the specification of both the OS and VR domains by promoting expression of OS (Pax2, Vax1b) and VR (Vax2) genes and repressing expression of DR genes (Tbx3, Tbx5). (B) During optic vesicle stages, the expression domains of Vax2 and Tbx3/5 become less dependent on Hh signalling (dashed lines), which is required to maintain Pax2 and Vax1b expression and proper OS development. At both stages, activation of Hh signalling is likely to depend on the Shh ligand, acting through inhibition of Gli repressor proteins (Gli-R) and increase of Gli activator proteins (Gli-A) [40]. Vax2 was previously shown to self-activate its own expression at optic vesicle stages [29].

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Neural Development

ISSN: 1749-8104