PROJECT SUMMARY/ABSTRACT This supplement grant application aims to support the professional development of a Black, female, veteran graduate student who is pursuing a career as a toxicology research scientist. To accomplish this goal, the candidate’s co-mentors – Dr. Thomas Sharpton and Dr. Robyn Tanguay – have worked with the candidate to develop a research, training, and mentorship plan that will ensure the candidate’s professional success. This plan includes an extensive interdisciplinary training program that incorporates both didactic and experiential learning modalities, as well as a personalized, intimate, and supportive mentorship program. Additionally, the plan includes an interdisciplinary and cutting-edge research project that will help the candidate catapult their career forward. In particular, the candidate will conduct research that extends the R01 parent award into complimentary, but new areas. Briefly, the parent award focuses on defining how early life exposure to pollutants impacts assembly of the gut microbiome to impair behavior development, and focuses specifically on benzo[a]pyrene as a model pollutant. As part of this supplement grant, the candidate will apply the tools and technologies developed under the parent award to investigate a specific class of environmental chemicals of concern, namely a diverse array of per- and polyfluoroalkyl substances (PFAS) that have been shown to impair behavior development in vertebrates. In so doing, the candidate will resolve how embryonic exposure to various PFAS impacts gut microbiome assembly and whether these alterations to the gut microbiome mediate how PFAS impair behavior. As a result, the candidate will obtain interdisciplinary experience in an emerging area of toxicology, especially with respect to bioinformatic and data science approaches, and will clarify potential mechanisms through which PFAS elicit their effect on vertebrate behavior. In total, the proposed plan will equip a passionate junior scientist from an underrepresented community to thrive in the competitive research landscape.