Fig. 2

Patterning of the Anterior Neural Plate Requires BMP Signaling at Pre- and Early Gastrula Stages(A–E) Embryos were treated with 10µM of DM (B–E) or equivalent volume of DMSO (A) at time points indicated. All embryos were fixed at bud stage followed by double in situ against foxg1 and rx3. (A, D, and E) Dorsal view, (B and C) animal pole view, and (A2–E2) sagittal section. DM treatment from 60% epiboly until bud stage results in partial rescue of the telencephalon at most anterior position (arrows in D and D2).(F–J) In rx3^/ mutants foxg1 expression is expanded across the eye field at one-somite stage (G), but not at bud stage (F). In DM-treated rx3^/ embryos (H–J), the expanded eye field expresses foxg1 in the entire rx3-positive domain, except at its margin and a small stripe of cells at the medial/ventral position (arrows in J). (F and G) Dorsal view, anterior to the top, (H) animal pole view, (I) lateral view, (J) sagittal section, ventral to the left. BS, bud stage; 1som, one-somite stage.