Bisphenol A (BPA) is a major environmental disruptor compound and after several decades in use as a plasticizer it is present in the blood of nearly all developing and adult humans. Exposure to this endocrine- active compound alters normal hormonal function, affects neural organization and ultimately can modify behavior and lead to neurological disorders. One mechanism by which BPA may act is via decreased DNA methylation causing dysregulated gene expression. I will identify persistent, epigenetic and behavioral changes following in utero BPA exposure. The exact targets of BPA-induced hypomethylation and/or its effects on gene transcription have not been fully characterized. In these studies, I will use a dose of BPA equivalent to that noted in humans and expose mouse embryos via maternal diet. BPA-induced changes in the developing brain of these mice will be identified using genome-wide methylome profiling in Aim 1. I will confirm the epigenetic changes at the level of DNA methylation using bisulfite sequencing and measure the concordant altered gene expression. From this, I will create a prioritized gene list for validation. In our model, BPA exposure decreases methylation of estrogen receptor alpha. In order to directly identify epigenetic modifications relevant to changes associated with BPA exposure, in the second aim, I will test estrogen receptor alpha knockout mice gestated on control or BPA diets for alterations in juvenile social behaviors. These studies will aid in the identification of BPA's molecular targets and potentially uncover genes that are epigenetically changed leading to altered behavior.