Role of nesfatin-1 in energetic state and maternal mouthbrooding in a cichlid .Chugh, S and Maruska, K Schugh1@lsu.edu Louisiana State University, Baton Rouge, LA. Feeding and energetics are fundamental processes in all species that must be balanced with reproductive investment.The regulation of reproduction and feeding is complex, with many hormones that act via central and peripheral mechanisms.While many regulatory molecules are well studied, a relatively new candidate peptide, nesfatin-1 (encoded by the nucb2 gene), has emerged as a key player involved in both feeding and reproduction across vertebrates. Studies in diverse vertebrate taxa show that it reduces appetite via central and peripheral regulation and has effects on reproduction.How nesfatin-1 might help regulate trade-offs between feeding and reproduction, however, is unexplored.The female cichlid fish Astatotilapia burtoni is an ideal system to examine the role of nesfatin-1 in feeding and reproduction because it cycles between a gravid feeding state while preparing to mate, and a forced starvation state while carrying the developing young in their mouths for ~2 weeks.To test whether female energetic state associated with mouthbrooding was linked with changes in the central nesfatin-1 system, we compared the number and size of nucb2-expressing cells in the brain of mouthbrooding, starved and fed females using in-situ hybridization. Using qPCR we measured nucb2 mRNA levels, also testing for similar differences in peripheral tissues(stomach, liver and intestine). Examining central and peripheral nucb2 levels in the same females helps explain the role of nesfatin-1 in allocating energy during the female reproductive cycle.Our study will lead to a better understanding of the evolution of nesfatin-1 regulatory pathways, which also has biomedical implications for treatment of obesity and diabetes.