Noxious peripheral stimuli are detected by nociceptive DRG sensory neurons; this information is transmitted to the superficial dorsal horn of the spinal cord, relayed to the brain, then perceived as pain. Previous studies have shown that Wnt signaling plays a crucial role during the development of nociceptive circuits. We have reported a transgenic mouse line in which Tau-LacZ is driven by the promoter of one Wnt receptor, Frizzled10. Here, we further characterize this transgenic mouse line and present our findings that nociceptive circuits were specifically labeled by the Tau-LacZ transgene in developing spinal cord and DRG. Tau-LacZ specifically labeled commissural axons crossing the floor plate and transmitting nociceptive information to the brain. Thus this mouse line will provide a powerful genetic tool for studying the development of spinal nociceptive circuits and the mechanisms of commissural axon guidance.