In-depth understanding of pathways to disease and preservation of good health necessitates the study of environmentally induced gene expression. Recent research has revealed that specific genes can be expressed at different points in an organism's life. Whether a particular gene is expressed and the degree to which it is expressed depend strongly on the environmental conditions experienced by the organism. Such gene expression is implicated in both positive and negative health effects.
Animal studies have been and will continue to be the main route to achieving deeper understanding of the mechanisms of gene expression. Environmental influences on gene expression in animal models include short-term early life influences (e.g., release of placental growth hormone, response to maternal stress hormones) and long-term responses to environmental conditions (e.g., physiological consequences of nurturing). The recent availability of gene chip technology provides the capability to identify changes in gene expression in response to environmental manipulations.
NIH should support integrative research aimed at understanding the role of environmentally induced gene expression in disease etiology and promotion of health. This should include:
studies that combine environmental manipulations with physiological and molecular assessments to provide refined understanding of conditions leading to dysfunction and, concomitantly, the mechanisms that preserve allostasis; investigation of connections between personal ties, the physical environment, and gene expression are particularly important;
studies that explore in animal models the relationships between chronic stress, interactions among intervening systems (e.g., hypothalamic-pituitary-adrenal axis, autonomic nervous system, immune system and overall central nervous system control of these systems), gene expression, and health outcomes;
initiation of studies using microarray chip technologies to monitor gene expression, associated with a broad range of environmental manipulations;
development of animal housing facilities, particularly for rodents, that more closely approximate species-specific habitats.
The preceding priorities (predisease pathways, positive health, and environmentally induced gene expression) all emphasize the importance of