Discover the evolutionary history of social bonding! This study presents an evolutionary timeline of the oxytocin signaling pathway, mapping the emergence of genes supporting oxytocin function across different phylostrata. This research provides insights into the origins of social behavior and its connection to psychological and somatic processes. Oxytocin is a neuropeptide associated with both psychological and somatic processes like parturition and social bonding. Using protein sequence similarity searches, microsynteny, and phylostratigraphy, the genes supporting the oxytocin pathway were assigned to different phylostrata. The majority (64%) of genes in the pathway are ‘modern’, evolving around the emergence of vertebrates or jawed vertebrates, including OXTR, OXT, and CD38. Most of the modern genes evolved around the emergence of vertebrates or jawed vertebrates, including OXTR, OXT and CD38. Functional analyses revealed that, in humans, medium-aged oxytocin pathway genes are highly expressed in contractile organs, while modern genes in the oxytocin pathway are primarily expressed in the brain and muscle tissue. This study provides a foundation for future research on the evolution of social behavior and its genetic basis.
Published in Communications Biology, this study is relevant to the journal's scope in evolutionary biology and genetics. By providing an evolutionary timeline of the oxytocin signaling pathway, the research contributes to understanding the genetic origins of social behaviors.