A role for juvenile hormone in the induction of antifreeze protein production by the fat body in the beetle Tenebrio molitor

Abstract 1. 1. Tenebrio larvae treated topically with JH-I and maintained under non-inducing conditions (16 light/8 dark photoperiod, 23°C and 90% relative humidity) elevated haemolymph antifreeze protein activity and concentration. 2. 2. Juvenile hormone (JH) titres (measured by radioimmunoassay) were elevated in larvae acclimated to antifreeze protein inducing conditions (short photoperiod or cold temperature). 3. 3. Fat bodies incubated in Grace's medium increased antifreeze protein when JH was added to the medium, but only when the fat bodies were taken from larvae which had been primed by a previous JH treatment.