The Wnt/beta-catenin signaling pathway establishes neuroanatomical asymmetries and their laterality

The vertebrate brain is an immensely complex structure, which exhibits numerous morphological and functional asymmetries. The best described brain asymmetries are found in the diencephalic epithalamus, where the habenulae and the dorso-laterally adjacent pineal complex are lateralized in many species. Research in the past decade has shed light on the establishment of the laterality of these structures as well as their asymmetry per se. In particular work in zebrafish (Danio rerio) has substantially contributed to our understanding, which genetic pathways are involved in these processes. The Wnt/beta-catenin pathway has turned out to play a pivotal role in the regulation of brain laterality and asymmetry and acts reiteratively during embryonic development.

► Wnt signaling is involved reiteratively during formation of vertebrate asymmetry.
► Axin1 mediated Wnt signaling establishes Nodal gene asymmetry in the brain.
► Wnt is required for correct placement of asymmetric internal organs.
► Wnt influences the asymmetric development of the zebrafish habenula neural circuit.