Fig. 5. DNA fragmentation and caspase-3 activation in the mantle and gill tissues from M. galloprovincialis specimens treated with various heavy metals. (A) (Left panel) DNA fragmentation induced by 1 µmol l^–1 CuCl₂ for 30 min, in the absence or presence of 1 µmol l^–1 SB203580, or 50 µmol l^–1 ZnCl₂ for 30 min in the mantle tissue. (Right panel) DNA fragmentation induced by 1 µmol l^–1 CuCl₂ for 30 min, 50 µmol l^–1 ZnCl₂ for 30 min or 1 µmol l^–1 CdCl₂ for 60 min in the gill tissue. Gels shown are representative of three independent experiments performed with similar results. (B) Specimens (four animals per group) were incubated in normal seawater (controls) or treated with either 1 µmol l^–1 CuCl₂ in the absence or presence of 1 µmol l^–1 SB203580, 50 µmol l^–1 ZnCl₂ or 1 µmol l^–1 CdCl₂ (for 30, 30 or 60 min, for each heavy metal, respectively). Endogenous full-length pro-caspase-3 and large active fragments of caspase-3 were detected using a specific rabbit monoclonal antibody in extracts (100 µg of protein) from mantle (top panel) and gill (bottom panel) tissues. Western blots shown are representative of four independent experiments performed with similar results. n.s., non specific.