Fig. 8.

Spatial distribution of LMX1B in WT and mutant limbs at E13. (A) Immunostaining of vibratome sections showing the distal region of E13 limbs from embryos of the indicated genotypes. Dorsal is up. The inset in the leftmost panel is an enlargement of the boxed area and shows the nuclear localization of LMX1B. White arrows point to the distal-dorsal region of the mutant limbs with reduced or absent LMX1B expression. (B) Whole E13 limbs stained with anti-LMX1B, anti-neurofilament (NF; nerve fibers) and GS-lectin (blood vessels). The immunostained nerve fibers, which are present in the limb interior, demonstrate the accessibility of the entire limb to the antibody probes. Blood vessels, visualized with GS-lectin, are present throughout the limb. The inset in the leftmost panel is an enlargement of the boxed area and shows the nuclear localization of LMX1B. (C) Additional whole limb immunostaining, as in B, showing the large-scale spatial arrangement of LMX1B-positive and LMX1B-negative cells in the indicated mutant limbs. All limbs in C were co-stained with anti-NF and GS-lectin to demonstrate probe access to the limb interior. DAPI staining (blue) shows the locations of nuclei. FL, fore limb; HL, hind limb. Scale bars: 0.5 mm.