GROWTH OF THE MALE ACCESSORY-GLAND IN ADULT LOCUSTS - ROLES OF JUVENILE-HORMONE, JH ESTERASE, AND JH BINDING-PROTEINS

The participation of juvenile hormone (JH) in the regulation of growth and protein synthesis in the accessory reproductive gland of male Loc usta migratoria has been investigated. After elimination of endogenous JH with ethoxyprecocene, the accessory gland failed to grow, but grow th was restored by a single application of the JH analog, pyriproxyfen . Pyriproxyfen appeared to stimulate total protein synthesis by 3 h, w ith a significant effect by 12 h, in contrast to 24 h observed in fat body. The dose curve for stimulation of protein synthesis 12 h after a pplying pyriproxyfen gave an ED(50) of 0.1 mu g; the dose curve for gl and growth at 72 h was biphasic, with steps at about 0.01 mu g and 10 mu g, suggesting two phases in JH action. SDS-PAGE analysis showed sev eral components that were stimulated by pyriproxyfen, the effect being strongest in an 11 kDa band. A 5 kDa component was enhanced in the so luble and reduced in the particulate fraction after precocene treatmen t. The accessory gland contained JH esterase activity at levels about 100 times those in fat body or hemolymph, and was higher in precocene treated locusts. Binding activity for [H-3]10 (R) under bar-JH III was high in cytosolic and nuclear fractions, and was identified immunolog ically as due to the previously described hemolymph JH binding protein . The results indicate that the mode of action of JH in the accessory gland may differ from that in the fat body. The presence of intracellu lar JH binding protein suggests a direct action of JH within the gland , that may be modulated by JH esterase. (C) 1995 Wiley-Liss, Inc.