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Fig. 1. Six3, Irx3, Gbx2, Dlx2 and Wnt3 expression in the
developing forebrain. (A-J) In situ hybridization of Six3 (A,B),
Irx3 (C,D), Dlx2 (E,F), Gbx2 (G,H) and
Wnt3 (I,J) at HH stage 7-8 (upper panels) and HH stage 19 (lower
panels). At HH stage 7-8, Six3 (A) and Irx3 (C) are anterior
and posterior to the prospective zli, respectively. At this stage,
Gbx2 (G) expression is confined to the prospective hindbrain, and
Dlx2 (E) and Wnt3 (I) expression is negligible. At HH stage
19, the expression domains of Irx3 (D), Gbx2 (H) and
Wnt3 (J) are posterior to the zli, whereas Six3 (B) and
Dlx2 (F) are expressed anterior to this structure. Arrowheads
indicate the position of the zli. Scale bar: 100 µm.