Small cationic antimicrobial peptides (AMPS) are host defense molecules detected in virtually all gropus of organisms. To investigate the immuine response mechanisms of Mytilus galloprovincialis, primary and suppresion subtractive hybridization libraries were prepared from hemolymph of mussels injected with heat-inactivated bacteria or ply l:C, the latter mimicking viral infection. After DNA sequencing, sequence processing and similarity searching, a remarkable abundance of AMP mRNAS were identified.Peer reviewed