Nutritional epigenetics.

Within the last two decades, significant progress has been made in understanding the importance of epigenetic mechanisms in the regulation of gene expression as a consequence of gene-environment interactions. Nutrition, among many other environmental factors, is a key player that can induce epigenetic changes not only in the directly exposed organisms but also in subsequent generations through the transgenerational inheritance of epigenetic traits. This article aims to provide insights into the usefulness of the mouse model for epigenetic studies involving nutrition as well as the inherent limitations when compared with epigenetic phenomena in humans. Mice are one of the most versatile models for nutrition and epigenetic studies because of several features, such as short life-span, relative low cost for generating samples, the existence of well-characterized genetically engineered lines, the detailed sequencing of genomes, and the relative similarity of their metabolic processes to human metabolism. However, several limitations have to be acknowledged, such as the different location of genes on the chromosomes (and hence possibly different consequences of some epigenetic alterations), differences in the epigenetic patterns established during late embryogenesis, and possible epigenetic differences associated with cellular senescence caused by the different structure of telomeres when compared with humans. All these aspects have to be carefully analyzed when deciding whether a mouse model should be considered for a study in nutrition and epigenetics. Consequently, the results obtained from mouse studies should be carefully interpreted regarding their relevance to humans.