POTENTIATION OF TENTACLE BALL FORMATION BY A TRYPSIN-LIKE PROTEASE AND ACCOMPANYING AUGMENTED INGESTION IN GLUTATHIONE-INDUCED FEEDING IN HYDRA

Tentacle ball formation may be a component of sequential feeding behav ior in Hydra. This behavioral response is elicited by reduced glutathi one after exposure to trypsin for 5 min at concentrations ranging from 0.1 fg/ml to 1 mu g/ml. Trypsin and thrombin potentiated this respons e more effectively than the other proteases examined. Trypsin signific antly promoted the ingestion of dead, fixed shrimp attached to their t entacles in the presence of glutathione. In an actual feeding situatio n, a trypsin-like protease, released from living wounded prey, may pot entiate tentacle ball formation, and as a result, the ingestion of pre y would be promoted in co-operation with reduced glutathione. We found that an immunoreactive protein for the monoclonal antibodies J245 and J5 was reduced in size in animals treated with trypsin; >300 kDa in a nimals without trypsin vs. 250 kDa or 110 kDa depending on the extent of trypsin treatment. Thus, this protein that is immunoreactive with J 245 and J5 is likely to be involved in the trypsin-dependent potentiat ion of tentacle ball formation and the promotion of ingestion.