Characterization of drosophila PARK8

Abstract

Drosophila PARK8(DPARK8) gene is a Drosophila homologue of human LRRK2 whose mutation causes autosomal dominant parkinsonism. DPARK8 gene consists of 7056 nucleotides with twelve exons and encodes 2351 amino acids protein containing ankyrin, LRR, ROC, and kinase domains conserved with its mammalian counterpart. Here, I generated and characterized a loss-of-function mutant and gain-of-function mutants for DPARK8 to investigate its physiological function. By using piggy bag transposable element insertion mutant as a loss-of-function mutant, immunohistochemistry and behavioral assays were applied. The defects in the gross structure of the neuromuscular system were not observed while fertility and fecundity were significantly reduced in the mutant females, which became severer with age. Also, the motor abilities of this mutants quantified by climbing assay were markedly decreased compared to wild type controls. Then, I examined the mitochondrial structures, muscle actin fibre arrays and the number of TH-positive neurons to further characterize the mutant phenotypes, but no significant defects were observed. In addition, overexpression of $DPARK8^{WT}$ and $DPARK8^{KR}$ by gmr-GAL4 and elav-GAL4 drivers caused degenerated eye phenotype and defective wing and incomplete cuticle formation, respectively. Taken together, using Drosophila system, I developed invaluable tools to study the pathogenic mechanism behind autosomal dominant parkinson’s disease (AD-PD) and established novel readout for future studying of parkinsonism.