Vitellogenin-like A–associated shifts in social cue responsiveness regulate behavioral task specialization in an ant

Division of labor and task specialization explain the success of human and insect societies. Social insect colonies are characterized by division of labor with workers specializing on brood care early and foraging later in life. Theory posits that this task switching requires shifts in responsiveness to task-related cues, yet experimental evidence is weak. Here we show that a Vitellogenin (Vg) ortholog identified in a RNAseq study on the ant Temnothorax longispinosus is involved in this process: Using phylogenetic analyses of Vg and Vg-like genes, we firstly show that this candidate gene does not cluster with the intensively studied honey bee Vg, but falls into a separate Vg-like A cluster. Secondly, an experimental knockdown of Vg-like A in the fat body caused a reduction in brood care and an increase in nestmate care in young ant workers. Nestmate care is normally exhibited by older workers. We demonstrate experimentally that this task switch is at least partly based on Vg-like-A-asso...