In this report we generated mice co-transgenic for a minimal promoter LacZ construct and a mouse BAC from the gene poor region upstream of the Hoxd cluster. In addition to expression in the distal limb, genital bud, and spinal cord, we show that this BAC transgene also reproducibly drives unique bilateral, dorsal posterior commissure expression. The ability of this BAC to direct posterior commissure expression makes it worthy of further study as a valuable tool in transgenic/targeting experiments.