Developmental plasticity is the ability to alter phenotype to accommodate environmental conditions during a critical development window. Pristionchus pacificus is a nematode model organism of plasticity as it exhibits mouth-form plasticity: either a predatory morph with two teeth, or a bacterivorous morph with one tooth. The Werner lab has recently found evidence that diet contributes to the mouth-form decision in juveniles, but it is not clear what the molecular signal of diet is that leads to changes in gene expression and ultimately phenotype. This pilot experiment aims to identify the molecular signal that conveys rich or poor nutrition. The PS312 and RSC019 strains of the P. pacificus species were cultured on agar plates with two main dietary restrictions: A semi-defined chemical axenic culture consisting of forty different chemicals, allowing fine-scale manipulation of different nutrients, and an oligidic axenic culture comprised of four chemicals. We are also culturing the strains in dietary restriction conditions of Heat-killed and UV-killed bacteria. Pilot data suggests that the wild isolate of P. pacificus, RSC019, grows much more poorly when cultured in UV-killed bacteria. However, the laboratory strain PS312 does not exhibit this effect - presumably due serial passaging and adaptation to laboratory conditions for over fifteen years. The RSC019 strain has been recently obtained from the wild and thus has yet to have an opportunity to evolve to lab conditions. This project aims to expand our understanding of the relationship between diet, development, and phenotype.