TFAM, a potential oxidative stress biomarker used for monitoring environment pollutants in Musca domestica.

Mitochondrial transcription factor A (TFAM) plays a key role in regulating the transcription, replication, and maintenance of mitochondrial DNA. In the present study, a Musca domestica TFAM (MdTFAM) gene was identified and characterized. MdTFAM gene encodes 253 amino acid residues, and the protein possesses two conserved motifs of HMG (High Mobility Group) box. Expression of MdTFAM was investigated based on the qRT-PCR (quantitative real-time polymerase chain reaction) in response to three model oxidative stress-inducing agents, cadmium chloride (Cd), doxorubicin hydrochloride (DOX) and ultraviolet (UV), respectively. Results showed that Cd exposure not only generated oxidative stress and mitochondrial dysfunctions in M. domestica larvae, with a significant increase in malondialdehyde and reactive oxygen species levels, but also induced a dose-dependent increase in the expression of MdTFAM. In addition, either DOX or UV exposure also significantly up-regulated the expression of MdTFAM in M. domestica larvae. These results suggest that MdTFAM play a vital role in maintaining the redox balance and its expression may serve as a useful biomarker for monitoring the oxidative stress induced by Cd, DOX or UV.