MOLECULAR MECHANISMS OF VERTEBRATE LEFT-RIGHT DEVELOPMENT

Patterning of all tissues and organs in the vertebrate embryo occurs a long the dorsoventral (DV), anteroposterior (AP), and left-right (LR) body axes. Whereas significant progress has been made in identifying t he processes underlying DV and AP patterning, relatively little is kno wn about mechanisms guiding LR development. The significant incidence of human disease conditions associated with LR laterality defects, par ticularly those of the cardiovascular system, underscores the importan ce of understanding how LR asymmetries become established in the embry o. The focus of this review is on recently identified genes that are i nvolved in generation of vertebrate LR asymmetry, and the proposed cel lular and molecular mechanisms by which they might function in initiat ion, propagation and interpretation of LR patterning information.