RT Journal Article
SR Electronic
T1 A small family business: synergistic and additive effects of the queen and the brood on worker reproduction in a primitively eusocial bee
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 756692
DO 10.1101/756692
A1 Margarita Orlova
A1 Jesse Starkey
A1 Etya Amsalem
YR 2019
UL http://biorxiv.org/content/early/2019/09/06/756692.abstract
AB The mechanisms that maintain reproductive division of labor in social insects are still incompletely understood. Most studies focus on the relationship between adults, overlooking another important stakeholder in the game – the juvenile offspring. Recent studies from various social species show that not only the queen, but also the brood regulates reproductive division of labor between females, but how the two coordinate to maintain reproductive monopoly remained unexplored.Our study aims at disentangling the roles of the brood and the queen in regulating worker reproduction in primitively eusocial bees. We examined the effects induced by the brood and queen, separately and together, on the behavioral, physiological and brain gene expression of Bombus impatiens workers. We found that young larvae induce a releaser effect in workers, decreasing egg laying and aggressive behaviors, while the queen induces both releaser and primer effects, modifying worker aggressive and egg laying behavior and reproductive physiology. The expression of reproduction- and aggression-related genes was altered in the presence of both queen and brood, but the effect was stronger or the same in the presence of the queen.We identified two types of interactions between the queen and the brood in regulating worker reproduction: (1) synergistic interactions regulating worker physiology, where the combined effect of the queen and the brood was stronger than each of them separately; (2) additive interactions regulating worker behavior, where the brood acts in a manner similar to the queen but to a much smaller extent and improved the quality of the effect induced by the queen. Our results suggest that the queen and the brood of primitively eusocial bees coordinate synergistically, additively, and sometimes even redundantly to regulate worker behavior and reproduction, and the interaction between them exists in multiple regulatory levels.