Project Summary The germline is dedicated to produce gametes that transmit genetic and epigenetic information to the next generation. Maintenance of germ cells and development of gametes require germ granules—well-conserved membraneless and RNA-rich organelles. The composition and function of germ granules remain elusive owing to their dynamic nature and their exclusive expression in the germline. This project addresses three fundamental questions. How are germ granules assembled and maintained? How are the epigenetic regulators, such as small RNAs, amplified in germ granules and passed on to offspring? What is impact of granules on gene regulatory networks and transgenerational inheritance? This proposal uses C. elegans germ granules as a model system to define their proteome and RNAome. The goal is to identify protein and RNA components that are required for germ granule formation, and characterize their role in germline maintenance and embryogenesis. Furthermore, the genetic and biochemical approaches afforded by C. elegans will be used to determine the mechanisms that drive the production of small RNAs within germ granules. By characterizing their constituents, this research program will advance our understanding of mechanisms of germ granule formation and their function in fertility.