Fig. 4. Expression of dorsal horn-specific molecular markers in wild-type and Lmx1b^-/- embryos at E14.5 (G-N) and E15.5 (A-E). (A,B) Hoxb6 expression in wild-type (A) and Lmx1b mutant embryos (B). (D,E) Spinal cord Hoxb8 expression is mainly evident in laminae I-II of wild type (D); however, in Lmx1b mutant embryo (E) its expression appears expanded ventrally. (C,F) Quantitative analysis of Hoxb6⁺ (C) and Hoxb8⁺ (F) neurons in wild-type (white bar) and Lmx1b^-/- embryos (black bar). (G,H) Expression of Lbx1 in wild-type (G) and Lmx1b mutant embryos (H). Broken white lines outline the dorsal horn and arrowheads indicate mispositioned LBX1⁺ neurons in Lmx1b mutant embryos. (I) Quantitative analysis of the number of LBX1⁺ neurons between wild-type and Lmx1b mutant embryos. (J,K) BRN3A⁺ expression in wild-type (J) and Lmx1b^-/- embryos (K) at E14.5. Arrowheads indicate the accumulation of BRN3A⁺ neurons around the midline (asterisk). (L) Quantitative comparison of the total number of BRN3A⁺ neurons between wild-type and Lmx1b^-/- embryos. (M,N) PAX2 expression in wild-type (M) and Lmx1b mutant embryos (N). (O) Numbers of PAX2⁺ neurons in wild-type and Lmx1b mutant embryos. Asterisks indicate the midline region. Scale bars: 200 µm in A,B,D,E; 100 µm in G,H,J,K,M,N.