qRT-PCR evaluation of the transcriptional response of zebra mussel to heavy metals

Joaquim Jaumot, Anna Navarro, Melissa Faria, Carlos Barata, Romà Tauler, Benjamín Piña

The transcriptional response of adult zebra mussels (Dreissena polymorpha) to heavy metals (mercury, copper, and cadmium) was analyzed by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) to study the coordinated regulation of different metal-, oxidative stress- and xenobiotic defence-related genes in gills and digestive gland. Regulatory network analyses allowed the comparison of this response between different species and taxa. Chemometric analyses allowed identifying the effects of these metals clearly separating control and treated samples of both tissues. Interactions between the different genes, either in the same or between both tissues, were analysed to identify correlations and to propose stress-related genes' regulatory networks. These networks were finally compared with existing data from human, mouse, zebrafish, Drosophila and the roundworm to evaluate their mechanistically-known response to metals (and to stressors in general) with the correlations observed in the still poorly-known, invasive zebra mussel. Our analyses found a general conservation of regulation genes and of their interactions among the different considered species, and may serve as a guide to extrapolate regulatory data from model species to lesser-known environmentally (or medically) relevant species.