Figure 6.

Epigenetic repression of iron sulfur flavoproteins in E. histolytica G3 strain. A) Semi-quantitative RT-PCR analysis of ISF1 and ISF2 expression levels in G3 parasites transfected with either empty vector (psAP2Gunma) or gene silencing plasmids (psAP2G-ISF1 and psAP2G-ISF2). cDNA from these cell lines (psAP2G, ISF1gs, ISF2gs) were subjected to 30 cycles of PCR using specific primers for ISF1 or ISF2. RNA polymerase was used as a control. PCR from samples without RT served as controls to exclude the possibility of genomic DNA contamination. B) Effect of ISF1 or ISF2 repression on the growth of trophozoites cultured under normal ("Normal") or L-cysteine-depleted ("CysDep") conditions. C) Effect of ISF1 or ISF2 repression on the tolerance of amoebic trophozoites to oxidative stress.