Epigenetics and the Biological Definition of Gene × Environment Interactions


concerning this article should be addressed to Michael J. Meaney, Douglas Mental Health University Institute, McGill University, 6875 LaSalle Blvd, Montreal, QC, Canada H4H 1R3. Electronic mail may be sent to michael.meaney@mcgill.ca.


Variations in phenotype reflect the influence of environmental conditions during development on cellular functions, including that of the genome. The recent integration of epigenetics into developmental psychobiology illustrates the processes by which environmental conditions in early life structurally alter DNA, providing a physical basis for the influence of the perinatal environmental signals on phenotype over the life of the individual. This review focuses on the enduring effects of naturally occurring variations in maternal care on gene expression and phenotype to provide an example of environmentally driven plasticity at the level of the DNA, revealing the interdependence of gene and environmental in the regulation of phenotype.