Generierung eines Drosophila melanogaster Modellsystems für die lysosomale Speicherkrankheit Morbus Fabry

In this work, a new animal model for the lysosomal storage disorder Fabry disease with the model organism Drosophila melanogaster was generated, characterised and established. It was furthermore used to develop new theories concerning the pathogenesis of this rare but fatal disease. This new model can be used universally, but was especially designed for the nephrologic aspects of Fabry disease. The two Drosophila genes CG5731 and CG7997 were identified to be the homologues of the gene GLA, which is mutated in patients with Fabry disease. Knockout-flylines, that had been generated by transposoninsertion, as well as RNAi-knockdownlines of both genes were ordered and their functionality tested with an established αGLA enzyme activity assay. Consequently, the lines were further evaluated with different techniques such as light- and immunofluorescence microscopy, electron microscopy, different methods to evaluate the endocytotic function of nephrocytes and RNAseq analysis. The CG7997 knockout and knockdownlines showed the most significant phenotype in nearly all of the experiments performed. The trasmissionelectron microscopy images of nephrocytes of the CG7997 knockoutline even showed the characteristic phenotype known from patient kidney biopsies, with the electrondense enlarged secondary lysosomes (zebrabodies). The nephrocytes of this line also showed deficits in their endocytotic function, which underlines the advantages of this model for all nephrocytic purposes. In addition to the characterisation of the two Drosophila genes, a disruption of the vesicle bound endocytotic pathway in nephrocytes of the CG7997 knockout could be shown. This evidence leads to new theories of the pathogenesis of Fabry disease. In other lysosomal storage diseases a similar phenomenom has been described, which further underlines the relevance of these findings. The aim of this work, to generate a new animal model for Fabry disease, was excelled with the results of the realised experiments. In the future, new theories and therapies can be developed and tested with the help of this new animal model