Novel feature of expression of the sarcotoxin IA gene in development of Sarcophaga peregrina.

The expressions of the sarcotoxin IA and IIA genes were investigated. Although both these antibacterial proteins were synthesized by the fat body and secreted into the hemolymph in the same way when the body wall of third instar larvae of Sarcophaga peregrina was injured, the expressions of their genes during development of this insect were different. The sarcotoxin IA gene was activated transiently in the embryonic and pupal stages, whereas the sarcotoxin IIA gene was totally inactive in these stages. These results suggest that sarcotoxin IA plays a role in the development as well as the defence mechanism of Sarcophaga.