A Conserved Regulatory Core — With Species-specific Innovations — at the Root of Shared Behaviors

Certain aspects of early development — including most types of cell-fate decisions and many aspects of determination of the body plan — proceed similarly in all metazoan organisms. Despite the wide diversity of eventual outcomes — specialized adult cell types, organs, body morphs and behaviors — these fundamental steps are also controlled by very similar cohorts of genes. In particular, conserved transcription factors (TFs) have been singled out for conserved and controlling roles. Likewise, certain fundamental aspects of social behavior are also deeply conserved. It seems possible that conserved gene regulatory programs may also underlie those conserved aspects of social response.

The overarching interest of our group is to identify gene regulatory network components that control fundamental aspects of development and behavior in mammals, and to examine how those networks have been modified for species-specific diversity. In a collaborative effort with other groups at the Institute, we have completed the first phase of a three-species comparison of neural response to territorial invasion, a social challenge that evokes a very clearly analogous response in most social species. Our studies, involving a gene expression and chromatin-mapping timecourse of brain regions from honey bee, stickleback, and mouse after exposure to territorial threat, reveal evidence of conservation of an ancient regulatory network that has been preserved, with species-specific modifications but with a clearly conserved TF backbone, from the earliest invention of social species. These studies provide new insights into the regulation of social behavior and provide a path to optimally leveraging data from diverse model species to understand social response, both normal and maladaptative, in humans.