Meeting Abstract
Dietary specialization is best investigated from the molecular to the whole organism level. Prickleback fishes (family Stichaeidae) are an excellent study system in which to study dietary specialization because they exhibit dietary variation in sympatric species, sister taxa with different diets, and feature convergent evolution of herbivory. The objective of this study was to determine the plasticity of prickleback gut length in response to dietary shifts and the genetic underpinnings of dietary specialization. We studied four species that naturally vary in diets: Xiphister mucosus (herbivore), Xiphister atropurpureus (omnivore), Phytichthys chirus (omnivore), and Anoplarchus purpurescens (carnivore). We assigned individuals of X. mucosus and A. purpurescens to omnivore or carnivore diets in the laboratory, whereas X. atropurpureus and P. chirus individuals were fed the carnivore diet. In wild fish, we observed the longest guts in herbivores, followed by omnivores and then carnivores. Similar effects of diet on gut length were observed in the laboratory-fed fish (omnivore > carnivore within a species). The transcriptomic profiles of pancreatic and mid intestinal tissues of wild-caught and captive fishes were examined using Illumina platforms. Genome-guided transcriptomic assemblies were performed with the reference genome of the prickleback Cebidichthys violaceus. We obtained of 16-20 million reads per tissue and analyses of differential expression and enrichment of genes involved in digestion and absorption of nutrients are underway. Overall, this study, will provide crucial insight into how vertebrates specialize to use specific resources, and how plastic the digestive system can be.
