Effects of dactinomycine (actinomycine D) on budless hydra and during its budding process

The effect of dactinomycine (actinomycine D) is manifested in various ways, which depends upon its concentration and animal condition at the time of treatment. Dactinomycine is citotoxic in stronger concentations so hydra dies quickly. In thinner concentrations it stops the mitotic activity of the cell, but the basic metabolic processes continue as before. Interstitial cells differenciate into cnidoblasts for some time, the cnid production is not halted, but all of these cells disappear as well as zimogen cells which dedifferentiate into gastrodermal interstitial and into mucous cells. Such animals live longer but die eventually. The effect of dactinomycine is generally milder on animals with a larger cell mass, in hydras with the budding tendency where exist such reserves and in those hydras in which the budding process has begun. In these a part of mobile undamaged zimogen cells can remain. They keep their reproduction ability. These animals can survive and keep on growing normally.