Fig. 5.

Prediction by intracellular early models of LR patterning of asymmetry phenotypes in embryo-splitting experiments. (A) If asymmetry is initiated by the action of cilia during gastrulation, very early blastomere separation should result in no loss of LR information and in normal nodal cilia. The resulting embryos are expected to exhibit 100% correct LR patterning. (B) In intracellular models, LR information provided by early, asymmetrically localized determinants is lost or altered in some daughter blastomeres upon early splitting, leading to the prediction of LR patterning defects, as is observed in human monozygotic twins and in experiments in amphibians.