YOLK PROTEIN IN THE PHARAOHS ANT - INFLUENCE OF LARVAE AND WORKERS ON VITELLOGENIN AND VITELLIN CONTENT IN QUEENS

Vitellin from the pharaoh's ant, Monomorium pharaonis (L.), was found to contain a single apoprotein with a M(r) of 198.3 kDa. The protein is a glycoprotein exposing mannose containing carbohydrate groups. Antibodies to pharaoh's ant vitellin (v(t)), raised in rabbits, were used to determine the head-, thorax-, and abdominal contents of vitellogenin and vitellin (v(g)+ v(t)) in queens in relation to the presence or absence of larvae and workers using an ELISA test. The v(g)+ v(t) contents were also compared to the egg-laying rate and the weight of the queens. The results confirm the existence of a positive correlation between v(g) + v(t) contents in the queens and their access to larvae, probably related to the queens' preferential feeding on larval secretions. In queens without larvae the abdominal v(g)+ v(t) contents declined in concordance with a low oviposition rate of 6-8 eggs/day. In spite of cessation of egg-laying within 24 hours after removal of both larvae and workers, the queens maintained basal contents of v(g)+ v(t). This may indicate that the presence of larvae is not only essential for the nutrition of the queens, but also for the uptake of vitellogenin in the growing oocytes. This additional stimultive factor may be based on the queens' response to primer pheromones liberated by the larvae. v(g)+ v(t) could not be demonstrated in workers or larvae with the ELISA test. If any v(g) + v(t) is pre sent in larvae and workers the amount is lower than the detection limit (1-2 ng/individual). This seems to rule out the possibility of transfer of proteins of this kind to the queens.