The juvenile hormone-carrier in the haemolymph of the acridine grasshopperGomphocerus rufus L.: Blocking of the juvenile hormone's action by means of repeated injections of an antibody to the carrier.

Egg-production, spermathecal enzyme activity and sexual behaviour inGomphocerus rufus females are shown to be controlled by the corpora allata, i.e. the juvenile hormone (JH). The haemolymph of this insect contains a high molecular weight glyco-lipo-protein (220,000; IEP 6.8) which has a high affinity for JH (Kd=5×10M). This protein binds JH selectively, even in competition with other haemolymph lipoproteins. Purification of the JH-binding protein and subsequent immunisation of rabbits yielded a homogenous antibody solution (Anti-JCv) which eliminated the JH-transport in the haemolymph if it was injected into adult males or females for several days after ecdysis. After this treatment the females did not produce eggs, and spermatophore-formation occurred only partially in the males, this indicating that the Anti-JCv-injections had exactly the same effect as bilateral allatectomy. The haemolymph of related grasshoppers was shown to contain a protein which is immunologically identical to the JH-carrier from theG. rufus haemolymph. It is suggested that the JH produced by the c. allata needs a protein carrier in order to exert its control on the functioning of the reproductive system. The synthesis of the JH-carrier is not dependent upon the presence of JH, i.e. the c. allata, since it is also produced by bilaterally allatectomized males and females throughout their whole life.