Changes in the activities of phosphorylase and UDPG-glycogen transferase in hamster eggs at the beginning of cell-differentiation

Abstract

Histochemical demonstrations of phosphorylase and UDPG-glycogen transferase were carried out using hamster eggs at the stage of blastomere-differentiation.
The results obtained were as follows.
1) Each blastomere of the 8-cell eggs 6570 hours after ovulation showed a strong phosphorylase reaction. Just before differentiation, four of the eight blastomeres of each egg exhibited a strong reaction, while the others showed none. In the differentiated 8-16 cell eggs 7175 hours after ovulation, only trophoblasts showed a weak reaction.
2) In most of the 8-cell eggs, each blastomere showed a moderate reaction of UDPG-glycogen transferase, whereas differentiated 8-16 cell eggs and blastocysts did not.