Use of RNA arbitrarily primed PCR to identify genomic alterations in the digestive gland of the freshwater bivalve Unio tumidus at a contaminated site.

The technique of RNA arbitrarily primed polymerase chain reaction (RAP-PCR) was developed to detect DNA damage and variations in gene expression in response to exposure to toxic compounds. This approach was tested on the freshwater bivalve Unio tumidus to explore the ability of RAP-PCR to detect effects induced by river sediment contaminated with polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs), and metals. In a first step the primer concentration was optimized to obtain reproducible amplifications of both high- and low-molecular-weight products. Optimized conditions allowed us to detect variations corresponding to the loss of PCR products in some animals exposed at the contaminated site compared with the control. Our results for the RAP-PCR approach performed on separate animals in field studies showed that interindividual variations could correspond to DNA damage and/or variations in gene expression.