Figure 7

Shh- expressing progenitors give rise to astrocytes in the hypothalamus. Immunostaining for glutamin synthetase (GS) and fate-mapped cells (β-gal or EYFP) (B, D, E, G, H, K), GFAP and β-gal (N) or NeuN and β-gal (L, O). Sections were imaged using a Zeiss Apotome setup. (A, B) In the tuberal hypothalamus, fate-mapped cells (TM8.5, green) are localized to the median eminence and display the typical morphology of tanycytes (arrowheads). (C-H) Tuberal hypothalamus. Fate-mapped cells with astrocytic morphology overlap with GS (arrows), and marked cells with neuronal morphology do not express GS. (I-K) Almost all fate-mapped cells in the preoptic area have astrocytic morphology and overlap with GS. (L) Only few fate-mapped cells in the preoptic area overlap with the neuronal marker NeuN. (M-O) Progenitors expressing Shh after E12.5 give rise to astrocytes but not neurons. Arrows indicate double-labeled cells. Scale bars: 800 μm (A, F, I); 100 μm (C, J, N, O); 40 μm (B, D, E, G, H, K, L). P, postnatal day.