Evidence of mtDNA amplification in response to benzene exposure: Armadillo officinalis Dumèril, 1816 as a bioindicator of air quality (Crustacea, Isopoda, Oniscidea).

Benzene exposure may cause cellular disease (Klauning & Kamendulis, 2004), which can result in modifications of mitochondrial DNA (mtDNA), probably as a response to oxidative stress in an effort to balance damage to the mitochondria. For this reason, the mtDNA copy number may be a good biomarker of the effects of benzene exposure. The general aim of this work was to validate the use of Armadillo officinalis Duméril, 1816 as a bioindicator of benzene exposure. The specific goal was the optimisation of a protocol for the evaluation of the increment of mtDNA copy number in relation to the nuclear DNA copy number, according to increasing benzene exposure in A. officinalis samples. The isopods were separated into three groups and exposed experimentally to different benzene concentrations. Real-time PCR (qrt-PCR) was performed for the quantification of mtDNA in relation to nuclear DNA. The preliminary data indicate that mtDNA, amplified by qrt-PCR, shows a trend to increased copy number in the groups exposed to increasing levels of benzene