Proteins synthesized before and after fertilization in sea urchin eggs.

Acrylamide-gel patterns of proteins made before and during the first 30 minutes after fertilization were the same. The patterns of gels containing proteins from eggs whose rate of protein synthesis was stimulated reversibly by prior anaerobiosis or removal of carbon dioxide were also the same as that of the mature unfertilized egg. Changes were detected in the pattern of proteins synthesized in gastrulas as compared to proteins made in unfertilized eggs or zygotes.