LEFT-RIGHT ASYMMETRY IN VERTEBRATES

All vertebrates develop with a distinct, invariant, left-right (L-R) b ody asymmetry. Recently, a number of molecules have been shown to be e xpressed asymmetrically with respect to the L-R axis during early embr yogenesis. The temporal expression patterns of these molecules, in com bination with embryo manipulation and genetic experiments, indicate th at they may represent elements of a conserved pathway governing embryo nic handedness.