With each generation, the precise spatio-temporal unfolding of embryonic development requires a tight orchestration of dynamic changes in chromatin states and corresponding transcriptional programs. While development is often approached as simply hardwired in the genome, there is a growing appreciation that the environment provides key inputs into the bookmarking and activation of the genome during ontogeny, but such inputs remain very poorly understood at the mechanistic level. Our lab is interested in understanding the genome-environment interactions that shape mammalian development and reproduction. Of particular interest are pluripotent cells that exist in the mammalian embryo and give rise to all cell types of the body. Recent work from our lab highlights that such foundational aspects as genome organization and gene transcription are regulated in novel ways in pluripotent cells of mammalian embryo, and that environmental perturbations sensed by these cells may lead to long-term consequences.