Biochemical Studies on the Early Development of the Sea Urchin

In vitro incorporation of amino acids into proteins stimulated by RNA from unfertilized sea urchin eggs.

Utilization of C14-glucose for amino acids and protein synthesis by the sea urchin embryo

Inhibitor of the Cytochrome Oxidase of Unfertilized Sea Urchin Eggs

IN a previous communication1 the presence of an inhibitor of cytochrome oxidase in the unfertilized sea urchin egg was described. It was shown that its activity decreases considerably following fertilization, that it is a low-molecular compound, that it is heat- and alkali-labile and that its action is of a competitive type.

An Inhibitor of Cytochrome Oxidase Activity in the Sea Urchin Egg

PREVIOUS work in this laboratory1,2 has demonstrated the presence of a highly active cytochrome oxidase in the isolated mitochondria of unfertilized sea urchin eggs. This activity is only 25 per cent lower than that of the mitochondria of the newly fertilized egg and up to the blastula stage2. No cytochrome oxidase activity has been found other than in the mitochondria1,3. On the other hand, it is known that the oxygen consumption of the unfertilized sea urchin egg is quite low; fertilization restores a normal respiratory level which increases continuously during the early development (for a discussion, see ref. 4). The suggestion was then made2 that in the unfertilized egg an extra-mitocho…