Biomonitoring marine environmental quality at the level of gene-expression- testing the feasibility of a new approach

Differential-display PCR (DD-PCR), a comparative method for detecting alter ations in the expression pattern of unknown genes, was applied to identify markers for environmental pollution of the coastal marine environment, in D onax trunculus (Mollusca: Bivalvia). Bivalves collected from a site typifie d by industrial pollution were compared with bivalves collected from an unp olluted site. Additionally, bivalves from the unpolluted site were exposed in the laboratory to increasing levels of pollution. Multiple responsive fr agments, including qualitative and quantitative differentials, were observe d in both experimental designs. Fragment-specific primers may be designed f or use in diagnostic amplifications, according to the sequence of selected differential fragments. This study is a first step toward the establishment of a marine warning and monitoring system based on the most basic level of biological response.