Fig. 3.

Proapoptotic activity of truncated Bid isoforms in Vero cells. (a) Vero cells were tranfected with either pCMV–myc (negative control), pCMVBid–myc, pCMVtBid-p13–myc or pCMVtBid-p15–myc. Full length and truncated forms of Bid, were detected using anti-myc-FITC (green). DNA was stained with Hoechst 33258 (blue). Cells transfected with active Bid forms showed nuclear features characteristic of apoptosis: nuclear size reduction, condensation and irregular chromatin pattern. In contrast, full length Bid transfection did not result in altered nuclear morphology. (b) Expression of truncated forms of Bid in transfected cells induced activation of caspase 3. (c) Vero cells expressing Bid truncated forms presented irregular mitochondrial clumping using a mitochondrial membrane potential-sensitive dye (CMXRos, orange). The finely reticular mitochondrial pattern is evident in non-transfected cells (arrows).