Fig. 2. Patterning defects in the diencephalon of Nkx2-1 mutant mice. (A-H) Serial sagittal sections through the brain of E11.5 wild-type (A-C) and Nkx2-1 mutant embryos (E-G) showing mRNA expression of Nkx2-4 (A,E), Pax6 (B,F) and Sim1 (C,G). The white arrowhead indicates the pallial-subpallial boundary, whereas the black (with white border) arrowhead denotes the LGE-MGE boundary. Note ventral expansion of Pax6 in the telencephalon (black arrows) and of Pax6 and Sim1 in the diencephalon (white arrow). (D,H) Schematic drawings summarizing the expression of pattern of Nkx2-1, Nkx2-4, Pax6, SF1 and Sim1 in the forebrain of wild-type and Nkx2-1 mutant embryos. (I-L) Serial sagittal sections through the brain of E18.5 wild-type (I,J) and Nkx2-1 mutant fetuses (K,L) showing immunohistochemistry for GABA (I,K) and calbindin (J,L). a/b, alar-basal boundary; ac, anterior commissure; DT, dorsal thalamus; fr, fasciculus retroflexus; H, hippocampus; Hb, hindbrain; Hyp, hypothalamus; Hyp*, mutant hypothalamus; ic, internal capsule; LGE, lateral ganglionic eminence; LGE*, mutant lateral ganglionic eminence; MGE, medial ganglionic eminence; MGE*, mutant medial ganglionic eminence; MHb, medial habenula; MM, mammillary hypothalamus; mt, mammillothalamic tract; mtg, mammillotegmental tract; NCx, neocortex; ob, olfactory bulb; p/sp, pallial/subpallial boundary; P, pontine nuclei; PT, pretectum; PV, paraventricular hypothalamic region; R, reticular nucleus; S, septum; S*, mutant septum; SC, superior colliculus; Teg, mesencephalic tegmentum; VM, ventromedial hypothalamic nucleus; VT, ventral thalamus; zli, zona limitans intrathalamica. Scale bar: 400 µm in A-C,E-G; 500 µm in I-L.
