Inhibition of putrescine synthesis blocks development of the polychete Ophryotrocha labronica at gastrulation.

Abstract

Developing eggs of the polychaete O. labronica were analyzed for polyamines during the first 6 days after fertilization. The spermine content dominated initially, but gradually decreased. It was surpassed by putrescine, which rapidly increased to a maximum on the 3rd day, i.e., at the inception of gastrulation. The spermidine content was low during the entire period. Treatment of eggs with the putrescine synthesis inhibitor .alpha.-methylornithine from the onset of development led to developmental arrest at gastrulation and to an abnormally low content of putrescine in the treated embryos. Methylglyoxal bis(guanylhydrazone), an inhibitor of spermine and spermidine synthesis, had no visible effect on development. Putrescine synthesis seems indispensable in early embryonic development of Ophryotrocha.