EFFECTS OF PLANT-LECTINS ON CELLULAR DEFENSE REACTIONS OF ASCIDIAN HEMOCYTES

The effects of plant lectins on the three cellular defense reactions o f hemocytes of the solitary ascidian, Halocynthia roretzi (hemocyte ag gregation, phagocytosis, and an allogenic reaction), were investigated . Concanavalin A inhibited aggregation, while wheat germ agglutinin an d ricin-inhibited the allogenic reaction. Neither of the lectins showe d inhibitory effects on phagocytosis, but ricin promoted phagocytosis. These effects of the lectins were diminished by the addition of sugar s specific for the respective lectins. These results strongly suggest that different surface carbohydrates are involved in the recognition m echanisms of three H. roretzi cellular defense reactions.