Effect of actinomycin D on antigen synthesis during sea urchin development

Publisher Website
Google Scholar
Abstract
Eggs and developmental stages of the sea urchin Paracentrotus lividus were incubated with radioactive (14C) amino acids. Incorporation of label into antigen was studied by means of rabbit antisera against sea urchin material. In an attempt to block genetic control of protein synthesis, eggs and embryos were treated with actinomycin D during different periods of development.During normal development the antigen‐labeling pattern, studied by immunoelectrophoresis and autoradiography, remained essentially unchanged until hatching. In the mesenchyme blastula, however, a new labeled antigen was detected, and one which earlier was unlabeled became heavily labeled. As seen in autoradiographs, during the same period, the intensity of labeling of other antigens also changed. When the embryos were exposed to actinomycin D (10–20 μg/ml) from hatching or some hours before, the development stopped at the mesenchyme blastula stage and these embryos never developed the labeling pattern characteristic of normal mesenchyme blastula.The results suggest that in contrast to the early development, gastrulation requires new production of templates. These templates seem to be essential for the changing pattern of antigen‐labeling. It is suggested that alterations in amino acid incorporation into antigens reflect changes in synthesis of proteins necessary for gastrulation.