Effective DNA regulation is the cornerstone of development, facilitating biological phenomena such as responses to the environment and cell specification. In each cell, DNA is packaged into chromatin, a malleable structure which can be manipulated to affect DNA stability and accessibility. Chromatin can be further categorized in actively transcribed and accessible euchromatin, and ultra-condensed and transcriptionally silent heterochromatin. Accurate delineation between these types of chromatin is imperative for all transcriptional regulation and successful development. Although effective chromatin function is crucial for life, the process in which euchromatin and heterochromatin are differentiated is poorly understood in many systems, especially vertebrates. My research aims to better understand the mechanisms driving heterochromatin establishment during vertebrate development.