The role of external tensions in differentiation of Xenopus laevis embryonic tissues

Explants extirpated from Xenopus laevis embryos at the early gastrula stage were placed on pieces of hydrophilized latex film which were then either stretched or remained intact. In explants cultivated on the intact films most cells emigrated out of the explants and remained undifferentiated, whereas the explants on the films stretched for 10 min or more developed a normal set of rudiments. In the explants of suprablastoporal zone stretched perpendicularly to the cranio-caudal direction, the axial organs were oriented in the direction of stretching. In the stretched explants, unlike the intact ones, a system of microfilament-associated intercellular contacts was formed within a few minutes.