Acid Phosphatase Activity in Perkinsus marinus, the Protistan Parasite of the American Oyster, Crassostrea virginica

Abstract

The effect of temperature (4, 12, 20, and 28 C) and osmolality (400, 570, and 840 mOsm/kg) on extracellular acid phosphatase (AP) secretion in vitro, and ultrastructural localization of AP activity in the parasite were investigated. The extracellular AP secretion by Perkinsus marinus was cell density dependent (P < 0.001). Increasing culture temperatures resulted in increased P. marinus proliferation concomitant with AP secretion (P < 0.0001). AP secretion was similar in P. marinus cultured at 400 and 570 mOsm/kg media, but higher than P. marinus cultured at 870 mOsm/kg media. Results of the ultrastructural study revealed that intense AP activity was in the nucleus of the parasite. Based on its distribution in the nucleus, AP may be playing a role in events leading to cell cycle regulation.