Figure 3

Panal A: Agarose gel picture showing expression level of metacaspase and Seryl transferase genes in rings (R), trophozoites (T) and schizonts (S) at different parasite densities (double arrow bar). NTC= No template control (Lane 13 ). RTC= Reverse transcription control (lane 14). Expression of metacaspase gene was stage dependent. At the ring stage metacaspase was absent until the parasite density reached 4%. For the trophozoites, the metacaspase gene was detectable at 0.54% and 3.68% parasitaemias while in the schizonts, the gene was present at all parasitaemia levels. The P. falciparum house keeping gene, seryl tRNA, was expressed at relatively equal level in all the RNA preparations. Panel B: Western blot analysis of P. falciparum protein extract probed with anti- caspase-7 polyclonal antibody. Protein fragments of 45 and 28 kDa were observed in all the developmental stages (lanes 1-12). Metacaspase protein was up-regulated starting from parasite density of 1.6% in all the parasite stages and remained up-regulated in subsequent parasitaemia levels except in the ring (lanes 7 and 10). Note a low levels of protein of 28 kDa in uninfected erythrocytes (lane 13) and has been reported before in other negative control samples. [16]