Mating Triggers an Up-regulation of Vitellogenin and Defensin in Ant Queens

Mating induces a range of physiological changes in female insects. In species that mate during several reproductive bouts throughout their life, mating causes an increase in oviposition, affects immune function, and decreases female lifespan and receptivity to further mating. Social Hymenoptera (ants, social bees, and wasps) are unique, since queens mate during a single reproductive effort at the beginning of their life. Their reproductive strategy is thus fundamentally different from that of other insects and one might expect the effects of mating on social Hymenoptera queens to be altered. We tested the effect of mating and multiple mating on the expression of six genes likely to be involved in post-mating changes, in queens of the ant Lasius niger L. We show that mating induces oviposition, and is followed by an up-regulation of vitellogenin and defensin expression. The expression of juvenile hormone esterase, insulin receptor 2, Cu-Zn superoxide dismutase 1, and prophenoloxidase is not significantly affected by mating. Queen-mating frequency did not affect the expression of the tested genes. Altogether, our results indicate that certain effects of mating on female insect physiology are generalized across species independent of their mating strategies, while others seem species specific.