The Cortical Tractor: A New Model For Epithelial Morphogenesis

We present here a new theory of epithelial morphogenesis based on the assumption that the cytoplasmic machinery responsible for epithelial cell motility is fundamentally similar to that of freely migrating mesenchymal cells. The additional constraint imposed on epithelial cells is that their apical borders remain attached. This model is able to mimic all of the foldings and invaginations of the earlier apical constriction model (Odell, et al., 1981). Moreover, it provides a mechanism for epithelial cells to actively change neighbors while maintaining the apical seal. This is an essential feature of epithelial morphogenesis, and the application of the model to neural plate formation is discussed in detail in Jacobson, Odell & Oster (1985) and Jacobson. Odell, Oster & Cheng (1986).