Abstract
Broom formation or broom-like aggregation of axopodia wasfound to be induced by treatment wth Con A (50 μg/ml) in the heliozoan, Echinosphaerium nucleofilum strain MA. This response was similar to capformation in lymphocytes. The broom formation was followed by axopodialdegradation and the subsequent cytolysis. At lower Con A concentrations (10to 30 μg/ml), broom formation was delayed considerably, while at higherCon A concentrations (90 to 125 μg/ml), axopodial degradation and cytolysisoccurred without broom formation. Pretreatment with 5×10-3 M colchicine or2 μg cytochalasin B/ml modified the Con A-induced axopodial broom formation, which was termed here as windmill formation. Pretreatment with 10-6 M PCMB or 10-2 M NaN3 inhibited both broom and windmill formation. Pretreatment with 10-4 M DNP produced no inhibitory effect on the Con A-induced axopodial rearrangement. The present data indicate that the ConA-induced rearrangement of heliozoan axopodia is closely related to cytoskeletal function.
