Neurosecretory control of haemolymph protein concentration during ovarian development in the desert locust

Abstract

The changes in haemolymph protein concentration were measured during ovarian development. A high haemolymph protein concentration was found to be correlated with an ‘active’ neurosecretory system and developing ovaries. Cautery of the neurosecretory cells of the brain resulted in a low haemolymph protein concentration; implantation of full corpora cardiaca, and hyperactivity, which releases neurosecretory material, elevated the haemolymph protein concentration. Rearing females with mature males was found to speed up maturation, and increase the build-up of haemolymph protein. The haemolymph amino acid concentration decreased when the protein concentration was high and increased when it was low, which suggests that it acts as a pool for protein synthesis. Three haemolymph protein fractions were demonstrated by electrophoresis; one of these increased greatly after ovariectomy and during yolk deposition and thus seems to be concerned in overian development. A neurosecretory control of protein synthesis is postulated.