Chemorepulsive axon guidance protein required for the development of spinal cord and forebrain commissures. Acts as a chemorepulsive guidance protein for commissural axons during development. Able to inhibit or repel neurite outgrowth from dorsal spinal cord. Inhibits the stabilization of cytosolic beta-catenin (CTNNB1) via its interaction with LRP6, thereby acting as an antagonist of Wnt signaling pathway. Interacts with LRP6. In embryonic brain, strong expression in the olfactory bulb, anterior olfactory nucleus, neocortex, piriform cortex, glial wedge, midline zipper glia, indusium griseum and the area surrounding the anterior commissure (AC) but not on AC axons (at protein level) (PubMed:23206892). Predominantly expressed in developing neural tissues. Expressed in many brain regions, including the olfactory bulb, cortex, midbrain, cerebellum and pontine nuclei in neonates. Detected in the dorsal spinal cord and commissural axons. In the forebrain commissures, it is expressed in the regions that surround the corpus callosum, hippocampal commissure, and anterior commissure, such as the midline glial cells, indusium griseum glia, and glial wedge. Mice are viable and fertile (PubMed:19150847). They however show a defasciculation of spinal cord commissural axons and absence of all forebrain commissures (PubMed:19150847, PubMed:23206892). Double knockout of Tsku and Draxi results in a higher frequency of anterior commissure defects than single knockout of either Tsku or Draxi (PubMed:23206892). Belongs to the draxin family.