Bulk Segregant Analysis of dFMR150M for Identification of Background Mutations

While investigating synaptic connectivity disruptions in a well-characterized Drosophila FXS disease model (dFMR150M, we found a synaptic overgrowth defect in the Giant Fiber neural circuit that depends on the genetic background in one null allele. Other FXS model strains did not manifest synaptic hyperconnectivity within this circuit, indicating that mutations have accumulated de novo in the background. Using bulked segregant analysis, we identify 8 QTLs containing these FXS background mutations.