A novel genetic model of dietary response and host-microbiota interactions
Diet-related disease outcomes stemming from both undernourishment and overconsumption represent evolutionary discordance: the human genome has been unable to evolve to match rapid dietary changes brought on by overpopulation and the agricultural and industrial revolutions. If we reveal pathways of genetic evolution taken by other vertebrates as they adapted to diverse diets, we should identify pathways for therapeutic intervention for pathological conflicts in humans brought on by maladaptive diets. East African cichlid fish species recently evolved diverse dietary adaptations, providing powerful strategies to understand the genetic basis of dietary response. Comparison of species across trophic levels (herbivore, omnivore, and carnivore) reveals species-specific differences in gut morphology, epithelial architecture, the gut microbiota, and feeding behavior; transcriptional comparisons suggest genes and genetic networks that may underlie these differences. Comparisons of whole genome sequence of dozens of species identify candidate genes for host metabolism and feeding behavior that have diverged consistently by trophic level. Quantitative trait loci mapping in an inter-species omnivore-by-carnivore cross is now revealing the genetic architecture of trophic traits listed above, including identification of host loci modulating the composition of the gut microbiota.
Arnold O. Beckman exemplifies the meaning of the word humanitarian. Combined with his unwavering enthusiasm for life, his keen sense of humor and his strong moral and ethical principles, he is a national icon.