Molecular and cellular effects induced by hexavalent chromium in Mediterranean mussels

► Significant molecular and cellular effects were observed in digestive gland of mussels exposed in vivo to Cr(VI) in the ng/L range. ► Lysosomal biomarkers indicated the development of a stress syndrome at 10 and 50 ng/L Cr(VI). ► Changes in mRNA expressions were seen at 1 ng/L Cr(VI) by a oligonucleotide microarray and Real-Time PCR. ► Expression profiles of stress-related gene products provide early signatures forecasting changes at higher levels of the biological organization.