Figure 1.

Pax2 protein expression in the mouse forebrain at E10.5 and E11.5. A-B, a-b: E10.5 sagittal sections showing Pax2 expression in the developing forebrain. In the ventral telencephalon, a few Pax2-positive cells can be detected in lateral sections (arrowheads in a) and become more abundant in more medial sections (a'). A few Pax2-positive cells are detected in the hypothalamus, close to the strongly Pax2-positive optic recess (or) area (B, b). The previously described staining in the future eminentia thalami of the diencephalon (asterisk in A) and the optic cup (arrowhead in A) are also shown. C, c: E11.5 sagittal sections revealing strong Pax2 expression in the developing septum (Se). No Pax2 expression is detected in the neighbouring lamina terminalis (LT) (arrow in c) at this developmental stage. Pax2-immunopositive cells are also found in the anterior hypothalamus (arrowheads in c) and may originate from the ventral neuroepithelium of the optic recess area (or). Expression in the eminentia thalami is not shown. Note the Pax2 expression in the spinal cord (SC) (arrows in C). a, b and c are high power images of the boxed areas in A, B and C respectively. a' is a high power image of a sagittal section at a more medial level than that depicted in a. Scale bars: C, 400 μm; A, B, c, 200 μm; a, a', b, 50 μm.