Identification of genes controlled by LMX1B in E13.5 mouse limbs.

During limb development, the dorsal limb mesenchyme expression of the transcription factor LMX1B is required for dorsoventral limb patterning. In mice, Lmx1b mutations result in the mirror-image duplication of ventral limb structures and loss of dorsal limb structures. Heterozygous LMX1B mutations in humans cause the Nail-Patella Syndrome characterized by limb, kidney, and eye developmental defects. We used DNA microarrays to compare the mRNAs in E13.5 mouse Lmx1b mutant and wild-type limbs. We report 14 genes that require Lmx1b for their normal expression in the dorsal limb or the restriction of their expression to the ventral limb.