Fig. 5. Abnormal region-specific OSN differentiation and normal region-specific gene expression in sustentacular and progenitor cells. In-situ hybridization analyses of serial coronal (dorsal up and medial left) sections of OE from control (A,C,E,G,I,K,M) and Lhx2^-/- embryos (B,D,F,H,I,L,N) using Dig-labeled cRNA probes specific for Golf (A,B), Omp (C,D), Nqo1 (E,F), Alk6 (G-J) and Msx1 (K-N). (A-F) Golf- and Omp-positive cells are present in all OE zones in control embryos (A,C) but show a restricted dorsomedial distribution in OE of Lhx2^-/- embryos (arrows in B,D). The distribution of Golf- and Omp-positive cells in Lhx2^-/- embryos is similar to the distribution of the dorsomedial-specific marker Nqo1 in control embryos (arrows in E). No Nqo1 expression over background is detected in Lhx2^-/- embryos (F). (G-N) The gradient of Alk6 expression (G,H; high dorsomedial and low ventrolateral) and the reverse gradient of Msx1 expression (K,L) are present in both control and Lhx2^-/- embryos. High-power magnifications of Alk6 expression in the sustentacular cell layer (I,J) and Msx1 expression in the basal progenitor cell layer (M,N) is shown. Thus, cells expressing Alk6 and Msx1 show a similar distribution in OE cell layers in control and Lhx2^-/- mice.