Genetically accurate models of SOD1-based ALS in Drosophila melanogaster

Abstract

ALS is a late onset, rapidly progressive and ultimately fatal neurodegenerative disease, caused by the loss of motor neurons in the brain and spinal cord. Generally, 5-10% of ALS patients have a family history (fALS), whereas there is no apparent genetic contribution for the remaining portion (sALS). Mutations in the SOD1 gene are responsible for 20% of fALS cases. Upon finding of the link between SOD1 mutations and ALS, researchers have begun to generate animal models based on different mSOD1-mediated ALS. Among various animal models, fruit flies stand out as an attractive model organism for studying neurodegenerative diseases with their small, yet still complex brains and also with their many advantages for being appropriate laboratory animals e.g. being small and cheap, having short reproductive and developmental cycles etc. Homologous recombination can be used for introducing disease-causing human mutations into endogenous Drosophila genes. Because endogenous gene regulation remains intact by this method, mutations introduced into endogenous Drosophila genes may provide accurate genetic models of disease. The aim of this thesis was to establish the methodology of HR using Drosophila as a model system at Bogazici University, NDAL laboratory in collaboration with Robert Reenan laboratory at Brown University. The specific aim of this study was to introduce two different ALS-linked human SOD1-mutations (G37R and H48R) into Drosophila dSOD gene. Within this study, these two mutations were successfully inserted into the dSOD gene. After backcrossing of the mutant lines to wild type line for sufficient generations in order to minimize background effects, these G37R and H48R mutant flies can be used as model organisms in ALS research.