Protein expression signatures and lysosomal stability in Mytilus edulis exposed to graded copper concentrations

Protein expression and lysosomal stability were observed in Mytilus edulis exposed to 0, 20, 40, 60, and 80 ppb copper sulfate for 24 h in a static ex posure system. Haemolymph was removed from each mussel and analyzed for lys osomal damage using the Neutral Red retention assay expressed as the ratio of lysosomal size to cell area, the lysosomal destabilization ratio. Gill t issue from the same individuals was dissected, homogenized and the proteins extracted and then separated using two-dimensional gel electrophoresis. Tw o-dimensional protein maps from each concentration were analyzed using MELA NIE II 2D gel analysis software (Biorad). Lysosomal damage increased with e ach dosage, with LDRs ranging from 0.18+/-0.01 at 0 ppb copper sulfate to 0 .32+/-0.11 at 80 ppb copper sulfate. Orthogonal comparisons showed that the central, 20 and 40 ppb classes together differed significantly (P < 0.05) from the 60 and 80 ppb classes together. Specific protein expression signat ures were identified at each dosage. (C) 2000 Elsevier Science Ltd. All rig hts reserved.