Parasitic organisms evolve to survive in numerous host environments. The parasitic schistosome worm is no exception and is the cause of schistosomiasis, a global disease affecting over 200 million people across 76 countries. The schistosome life-cycle is characterized by remarkable phenotypic and genetic transitions between a molluscan host, a mammalian host and a free swimming larva, and may live for up to 30 years. The transcriptional regulators involved in directing gene expression to control these diverse transformations are unknown. My research focus is to identify key regulators of schistosome gene expression and their targets and determine the mechanism of transcriptional control in response to developmental and environmental cues.