Figure 1 A dynamic spatiotemporal gradient of gli activation correlates with transcription factor expression domains. (A–F) Transverse section of neural tube of the gli binding site transgenic reporter mouse. Tg(GBS–GFP) shows GFP expression in cells that are actively transcribing Gli genes, which demonstrates a ventral to dorsal gradient that peaks in its intensity and dorsal distance at 18h, followed by a gradual decline over time. This temporal change is pictorially represented in (H). Early gene expression domains of Nkx2.2Olig2, and Pax6 have significant overlap; however, by 52h this pattern becomes progressively more refined over time. This refinement is pictorially displayed in (G).

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