Epigenetic mechanisms are fundamental to eukaryotic biology: they govern the use of the information encoded in DNA, and by allowing for selective expression of genes make it possible for an organism to use the same genome to create many very different cell types. The phenotype of an organism is thus largely based on epigenetic mechanisms, and aberrations in these mechanisms can create variation, and also cause disease. In this presentation I will discuss our contribution to understanding  epigenetic variation, its inheritance, and its sensitivity to environmental factors such as nutrition.