On the water-soluble protein of sea urchin eggs and its changes during the early development

Summary In the egg of sea urchin,Hemicentrotus pulcherrimus, changes in the amount of water-soluble protein were observed chromatographically. There were three kinds of group (A, B, and C) in the protein pattern by thin-layer chromatography with Sephadex gel (G-200) and each group contained several components. The molecular weight was 30,000–90,000 in group A, 90,000–480,000 in group B, and more than 480,000 in group C, respectively. The area which belonged to group C reduced remarkably upon fertilization and the opposite aspect was observed in groups A and B. This suggests the possibility of the attack of proteolytic enzyme which induces subsequently an increase of small molecular substances. In later stages, the area of group C might recovered neary to that of the unfertilized egg at a sacrifice of group A. The rearrangement of proteins possibly may take place after the fertilization.The relationship between the water-soluble protein and fertilization phenomena is discussed with the presence of the experimental results.