Early onset torsion dystonia is caused by mutations in DYT1 gene in humans. Two deletion mutations and one missense mutation were found from patients with this devastating disorder. The molecular and cellular etiology underlying this disorder is not still understood yet. Because vertebrates have more than 4 homologs in their genomes, it is very hard to elucidate the exact in vivo functions of Torsin1A. Instead, Drosophila has only one homolog named Torsin. To investigate the in vivo functions of Torsin, we generated and characterized transgenic flies expressing coding regions of Torsin mRNA or double stranded inhibitory DNA constructs (RNAi). The specific antibodies for Drosophila Torsin (DTor) also were generated. The transgenic expression of DTor cDNA or RNAi in all tissue induced significant changes in DTor proteins levels. Even though expression of DTor cDNA in neuronal system increased the amount of DTor proteins, expression of DTor RNAi did not significantly altered the amount of DTor. Consistent with this result, the numbers of flies with motor-activity were not discernible among neuronal expression lines. However, flies expressing DTor cDNA or RNAi on muscles showed significantly altered locomotor ability, suggesting that DTor plays important roles in regulating motor-activity at the post-synaptic terminals of motor neurons. In addition, DTor over-expressing flies showed increased resistance to H2O2. In the future study, we will found how those phenotypes were accomplished by performing various experiments. (NRF-2012R1A1A4A01011674: HRF-S-201.-6)