Cooperative behavior, where individuals act together for a shared benefit, is common across the animal kingdom. Research on cooperation has provided compelling explanations as to why and how cooperation evolved; for example, why vampire bats regurgitate food to feed hungry roost-mates, or why marmots risk survival to warn neighbors about predators. Despite this ultimate understanding of cooperation, almost nothing is known about the physiological mechanisms influencing cooperative behavior, such as which genes and brain regions are involved. Furthermore, the extent to which the mechanisms underlying cooperation are similar across species is unknown. This research will provide novel insights into the mechanisms underlying cooperative behavior and how these mechanisms evolve. Given that humans exhibit some of the most complex forms of cooperative behavior of any species, insight into the causes and origins of cooperation will offer insight into the human condition. Why and how animals cooperate is of interest to a broad audience. As such, the results of the work will be communicated through several public outreach programs, including an internship program for high school students. In addition, the collaborative nature of this research provides unique educational opportunities to students in the US and to international students who otherwise would not be exposed to integrative and genomic approaches in brain and behavior research.
Although cooperative behavior is widespread in animals, and its function and evolution are well understood, the neuromolecular underpinnings of cooperation have not been examined in any detail. Using brain region specific transcriptomic analyses, the proposed research addresses two fundamental questions: (1) the extent to which patterns of gene expression, or gene modules, modulate individual variation in cooperative behavior, and (2) the degree of molecular convergence for shared traits across species. The well-studied cleaner-client mutualism in fishes, where 'cleaner' fish service 'client' fish by removing ectoparasites and dead tissue their mouths, will be used to identify the neuromolecular correlates of cooperative behavior. Specifically, to identify gene modules associated with cooperation, and its evolution, the transcriptomes from two brain regions from wild-caught cleaner wrasses (from species pairs of cleaners and non-cleaners, where cooperation has evolved independently) will be analyzed: the amygdala for its role in emotional processing and the hippocampus for its role in social cognition. The results of this innovative study will provide for the first time insights into the neuromolecular basis of cooperation. Furthermore, the proposed work will inform our understanding of behavioral evolution by integrating both ultimate and proximate mechanisms, and will provide insight into whether neuromolecular mechanisms constrain or facilitate the evolution of behavioral phenotypes.
