Reproduction in social insect societies is dominated by one or a few females and exhibits one of the most fascinating phenomena in social behavior; some individuals forego reproduction and only raise their siblings. Such an extreme reproductive skew is maintained by sophisticated behavioral and chemical mechanisms and requires the transfer of genetic traits which encode behaviors that seemingly sabotage their own inheritance. This project seeks to understand how social insect reproduction is regulated by examining the behavioral, chemical and genetic regulators of worker sterility at different scales within a single species of bumblebee. Bumblebee life cycles span several levels of social organization, allowing the unique opportunity to study changes in regulatory patterns of reproduction as the colony develops. These discoveries will lay the groundwork for future studies of the mechanisms underlying worker sterility, the evolution of sociality and social communication. The integrative nature of this research creates a unique platform to increase diversity by targeting underrepresented groups at different stages of development. This will be accomplished by (1) developing a novel, yearly program to increase networking and exposure to science in underserved populations of undergraduate students in Pennsylvania; (2) developing an insect communication module for the Upward Bound Program that exposes promising low income and first-generation high school students to college experiences; and (3) using the qualities of bumblebees as key worldwide pollinators to increase awareness of the importance of pollinators in K-8 students. Funds will support an interdisciplinary training in behavior, chemical ecology, and genomics to students and scholars.
The mechanistic basis of pheromones regulating reproduction in the sterile worker caste of social insects is one of the greatest puzzles in social evolution since helper females refrain from reproduction (seemingly against their interests), and the signaling systems maintaining reproductive division of labor are susceptible for cheating. This CAREER project examines the behavioral, chemical and genetic mechanisms regulating reproduction in insects and the role the social context plays in shaping these interactions. The team will: (1) Characterize the synergetic effects of behavioral and chemical signaling regulating reproduction; (2) Examine the importance of social context to the regulatory mechanisms; (3) Unveil the genetic regulation of workers’ brain gene expression responses to cues regulating reproduction. The project focuses on the reproductive mechanisms used by a sole queen, nestmate workers and the brood in the bumble bee Bombus impatiens. These efforts will uncover the interplay between dominance behavior and chemical signaling in regulating reproduction and the genetic basis of sterility-inducing pheromones.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
