Periconception in Physiology and Medicine

William V. Holt, Holt, William V.

Model organisms are widely used in research that is ultimately aimed at understanding the causes and consequences of human disease. It may seem counterintuitive to expect clinically useful information to be obtained from species as diverse as fishes and insects, but because fundamental biological mechanisms share evolutionary origins they transcend species barriers. Epigenetic mechanisms fulfil this expectation admirably as more and more is discovered about the basic operational rules of inheritance, which are much more elaborate than formerly thought. Only a few decades ago, although the complex interplay between genes, inheritance and the environment was recognized, it was difficult to explain. Recent discoveries about the controlling influences of gene silencing through DNA and histone methylation, the roles of so-called non-coding DNA and microRNA, and the way in which these factors respond to environmental conditions have started to shed light on these basic mechanisms. Diverse model species allow epigenetic mechanisms to be studied from different perspectives; for example, some are better suited to studies of sex determination while others may be more convenient for studying the earliest stages of organ development, growth and the influence of nutrition on future wellbeing. The rationale for including this chapter in a book that is focused on uncovering relationships between periconception nutrition in humans is to highlight the opportunities and insights that may be gained by focusing attention on studies in non-mammalian model species.