Protein synthesis in micromeres of the sea urchin egg

A method was developed for isolating large quantities of micromeres from the 16-cell stage of the sea urchin, and measurements were made of their ability to incorporate C(14)-L-valine into protein as compared with that of a mixed suspension of micromeres, mesomeres, and macromeres. Per cell, the rate of incorporation was considerably less for the micromeres than for the suspension of mixed cells. Per unit volume, however, the two types of suspensions showed no significant differences.