Control of a sex-limited haemolymph protein by corpora allata during ovarian development in Periplaneta americana (L.).

Abstract

1. The removal of corpora allata from females of the roach, Periplaneta americana, soon after the imaginal molt prevented growth and yolk formation in the oocytes.2. No immediate effect on ovarian development was noticed when mature adult females were allatectomized.3. The haemolymph protein concentration of allatectomized females failed to reach the level of the sham-operated female roaches of the same age.4. Electrophoresis of haemolymph proteins on cellulose acetate strips revealed a gradual decrease and final disappearance of one of the main protein fractions in the allatectomized females.5. The haemolymph protein concentration of ovariectomized roaches rose to a level far in excess of that of sham-ovariectomized roaches of the same age. A significant increase in protein fraction 5 has been observed in the ovariectomized roaches compared with that of sham-ovariectomized roaches.6. In male roaches fraction 5 remained at low concentration at all times, suggesting that protein fraction 5 is sex-limited in character.7. Allatectomized roaches exhibited a slower rate of incorporation of tritiumlabelled amino acids into haemolymph proteins than the sham-operated roaches.8. It is concluded that the effects of corpora allata on egg maturation and yolk deposition may be due to their influence on metabolic processes, particularly the synthesis of a sex-limited haemolymph protein which presumably enters the growing oocytes.