Yolk protein in the pharaoh's ant: Influence of larvae and workers on vitellogenin and vitellin content in queens

Summary Vitellin from the pharaoh's ant,Monomorium pharaonis (L.), was found to contain a single apoprotein with aM_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. Thev_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 betweenv_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 abdominalv_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 ofv_g+vt. 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 anyv_g+vt is present 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.