Immunity Defects in the Drosophila Model of Fragile X Syndrome. Elizabeth Stone, Mimi Shirasu-Hiza. Columbia University, New York City, NY.

   Fragile X Syndrome (FXS) is the most common monogenic cause of intellectual disability and autistic behaviors. In FXS, the silencing of FMR1, the gene that encodes the translational regulator FMRP, causes altered neuronal signaling and firing, leading to defects in learning, memory, behavior, and circadian regulation. Patients with FXS also exhibit changes in immune system parameters. The Drosophila homolog of FMR1, dfmr1, is highly conserved, and dfmr1 mutants have neuronal and behavioral defects similar to those seen in vertebrates. The immune system function of dfmr1 mutants has not yet been examined. We find that dfmr1 mutants are highly resistant to certain bacterial pathogens. We are examining specific immune mechanisms that may be responsible for this phenotype. Because FXS and autistic patients appear to have abnormal immune system function, this work may have implications for therapeutic interventions.