Effects of cytochalasin H on developing frog embryos: reversibility of action.

Cytochalasin H (CH) brought about cellular disaggregation resulting into arrest of development in the embryos of the frog, Microhyla ornata. The effects were dependent on the dose of CH, duration of the treatment as well as on developmental stage of the embryo at the beginning of the treatment. The embryos were protected to some extent if the vitelline membranes were left intact. The reversibility of CH-action, after transfer of treated embryos to CH-free medium, was dependent on the extent of cellular disaggregation brought about by CH and on the presence or absence of an intact vitelline membrane.