1471-0056322002FebNat Rev GenetEstablishment of vertebrate left-right asymmetry.103113103-13The generation of morphological, such as left-right, asymmetry during development is an integral part of the establishment of a body plan. Until recently, the molecular basis of left-right asymmetry was a mystery, but studies indicate that Nodal and the Lefty proteins, transforming growth factor-beta-related molecules, have a central role in generating asymmetric signals. Although the initial mechanism of symmetry breaking remains unknown, developmental biologists are beginning to analyse the pathway that leads to left-right asymmetry establishment and maintenance.HamadaHiroshiHDivision of Molecular Biology, Institute for Molecular and Cellular Biology, Osaka University, and CREST, Japan. hamada@imcb.osaka-u.ac.jpMenoChikaraCWatanabeDaisukeDSaijohYukioYengJournal ArticleResearch Support, Non-U.S. Gov'tReview