Presence of acid phosphatase activity in heavy bodies of sea urchin eggs

Abstract

Cytochemical studies were made on the acid phosphatase (Acp-ase) in the heavy bodies of eggs of the sea urchins, Hemicentrotus pulcherrimus and Temnopleurus toreumaticus, from the stage of mature unfertilized eggs to the late gastrula stage. High Acp-ase activity was found in masses composed of ribosome-like granules in the heavy bodies from the early stage of the formation of heavy bodies until the time of their disappearance, whereas the annulate lamellae and the space between the annulate lamellae and the masses packed with ribosome-like granules did not have activity. This activity was inhibited by the addition of 0.01 M NaF to, or the omission of substrate from, the Gomori medium. Using the reaction products of Acp-ase and the masses of ribosome-like granules as markers of heavy bodies, we found small groups of tightly packed ribosome-like granules that were not surrounded by annulate lamellae. The function of Acp-ase in the heavy bodies is still unknown.