ABSTRACT
Recent advances have made screening of model organisms a practical alternative for understanding genes and pathways involved in energy storage and utilization, as well as life span. For example, Caenorhabditis elegans, Drosophila, and zebrafish are highly amenable to genetic screening, and mutant animals can be further analyzed with high throughput transcriptomics, proteomics and metabolomics. Thus, these species promise to guide work in higher organisms on complex interactions between nutritional environment and the genome, epigenome, and proteome. Whole-body energy balance is influenced by appetite, digestion and absorption of nutrients, as well as metabolism, and these ancient processes tend to be highly conserved across species. Research on model organisms, especially in conjunction with research on rodents, provides important information on basic mechanisms of energy balance, and holds the promise of speeding development of new treatments for obesity and diabetes in humans. However, probably the greatest potential insight from model systems will come from processes that we would not necessarily be able to predict. For example, the discovery of micro-RNAs, which appear to be important regulators of gene expression in mammals, came about from unexplained genetic observations in plants. In addition, model systems have helped guide research in higher animals in the area of aging, where complex genetics and long life span limit work in mammals. Of the model organisms, we will review the potential for C. elegans, Drosophila and zebrafish to provide insights into basic metabolic processes as well as insight into obesity.
