(597g) Essential Factors Promoting Long-Term Cell Survival and Growth of Drosophila Cells in Chemically Defined Media

Drosophila cell culture finds multiple applications as a screening platform to identify novel targets and therapeutics to treat human diseases and as an expression system for generating recombinant proteins. In an effort to define and characterize the minimal essential requirements for maintaining long-term growth of Drosophila cell lines, we have performed a medium-throughput screen for small molecule compounds that promote cell proliferation in a chemically defined medium. Multifactorial secondary screening provided an efficient method for validation of the candidate growth supplements and identification of important synergies between medium components. For the screening efforts, we focused on an epithelial cell line, Cl.8, which is well characterized and has been previously used to identify novel insect-specific growth factors. We have characterized candidate molecules relevant to stimulating growth and survival of both imaginal disc-derived Cl.8 cells and the industrially relevant cell line Drosophila S2. We found that one factor promoting autophagy in particular is critical for enabling multiple passages in a chemically defined medium.  Expansion of our pilot screen will enable identification an optimal combination of small molecules that can support the maintenance and generation of new Drosophila cell lines, increasing the versatility of Drosophila as both a genetic and biochemical model system.