FIG 2 .

var2csa intron deletion results in upregulation of transcription in ring-stage parasites. (A) RNA was isolated from highly synchronized ring-stage parasites (12 hpi) from a CSA-panned FCR3 culture (top panel, yellow), a 3D7 WT bulk culture (second panel, black), an intron KO telomere mutant clone (third panel, red), and six var2csa intron KO mutant clones (fourth, fifth, and sixth panels). RT-qPCR analysis of all var genes was performed, and cDNA levels were normalized to those of serine-tRNA ligase. Intron KO clone A is shown in the fourth panel in green along with three other clones (in gray) showing similar monoallelic transcriptional var profiles. Intron KO clones B (fifth panel in purple) and C (sixth panel in blue) transcribed multiple var genes. A gray dashed box indicates the var2csa gene, Pf3D7_1200600. (B) RNA was isolated from highly synchronized parasites from a CSA-panned FCR3 culture (yellow); a 3D7 WT bulk culture (black); intron KO mutant clones A (green), B (purple), and C (blue); and an intron KO telomere mutant clone (red) at 12 (ring), 24 (trophozoite), and 36 (schizont) hpi. RT-qPCR analysis of Pf3D7_0412700 (upsC var gene) and Pf3D7_1200600 (var2csa) was performed, and var gene cDNA levels were normalized to those of serine-tRNA ligase.