||Organismal survival depends on properly sensing nutrients. The fission yeast, Schizosaccharomyces pombe, and the budding yeast, Saccharomyces cerevisiae, both de-repress their phosphate signal transduction (PHO) pathways in response to low inorganic phosphate levels as well as low adenine levels. This thesis aims to study the elements common to both yeast species in order to gain a better understanding of the mechanism behind the adenine cross-regulation in S. pombe, and in the process, further characterize the S. pombe PHO pathway. Through using genetics and epistasis approaches in S. pombe, the interactions of predicted components of the PHO pathway were assessed through examining acid phosphatase levels. This study confirmed the roles of the transcription factor, Pho7, and a component of the chromatin remodeling system, Snf5, as downstream components of the S. pombe PHO pathway. The novel S. pombe PHO pathway model has three distinct regulatory arms that modulate acid phosphatase expression.