Juvenile hormone control of female specific protein synthesis in Leucophaea maderae, Schistocerca vaga, and Sarcophaga bullata

Abstract

In Schistocerca vaga a female specific protein is present in the haemolymph during egg maturation. This protein is absent from the haemolymph before the start of ovarian development, in females allatectomized before the start of ovarian development, and in males of any age. This female specific protein has been shown to be immunologically identical with the major yolk protein. Application of juvenile hormone (JH) to allatectomized females results in the appearance of small quantities of female specific protein in the haemolymph. Experiments involving neurosecretory cell cauterized animals failed to confirm or deny the involvement of neurosecretion in the control of protein synthesis. In Leucophaea maderae JH alone controls the synthesis of a female specific protein. This protein is probably synthesized in the fat body which in vitro is five times more active in incorporating 14C-leucine into protein in egg maturing animals than in allatectomized animals. Addition of corpora allata (CA) to the incubation medium does not increase the protein synthetic activity of the fat body. In Sarcophaga bullata the female specific protein is synthesized in some but not all allatectomized animals. After extirpation of the neurosecretory cells very little yolk is deposited in the oöcytes, even though female specific protein is present in the haemolymph. In this species 10,11-epoxyfarnesenic acid is more potent in inducing female specific protein synthesis in allatectomized females than the all- trans isomer of the cecropia hormone. In Sarcophaga there is clear evidence of a dual control of egg maturation.