FIG 4 .

An intronless var2csa gene can be silenced via long-term culture or CD36 panning, then reactivated with CSA panning. RNA was isolated from highly synchronized ring-stage parasites (12 hpi) from a 3D7 WT bulk culture (black) and var2csa intron KO mutant clone A (gray). RT-qPCR analysis of all var genes was performed before (“Initial Culture,” top panel) and after (“Long-term Culture,” second panel) 2 months of continuous culture. The initial cultures were also subjected to three rounds of CD36 panning (third panel), followed by three rounds of CSA panning (bottom panel). var gene cDNA levels are normalized to those of serine-tRNA ligase. A gray dotted box indicates the var2csa gene, Pf3D7_1200600.