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. Author manuscript; available in PMC: 2010 Sep 1.
Published in final edited form as: Mol Microbiol. 2009 Aug 24;73(6):1171–1185. doi: 10.1111/j.1365-2958.2009.06846.x

Figure 5.

Figure 5

var, rifin, stevor, and Pfmc-2TMs are share a common factor required for efficient expression. (a) Change in var RNA levels following increase in copy number of pRBH. Expression levels are shown of endogenous var genes in pRBH/C3 parasites under low (black bars) and high (grey bars) blasticin doses. (b) Representation of data depicted in (a). Total var transcript levels of pRBH transfected C3 parasites under low (black bar) and high blasticidin doses (grey bar). The approximate copy number of the transfected episome for each drug concentration is shown in parentheses. (c) Change in var RNA levels following increase in copy number of pSBH. Expression levels are shown of endogenous var genes in pSBH/C3 parasites under low (black bars) and high (grey bars) blasticidin doses. (d) Representation of data depicted in (c). Total var transcript levels of pSBH transfected C3 parasites under low (black bar) and high blasticidin doses (grey bar). The approximate copy number of the transfected episome for each drug concentration is shown in parentheses. (e) Change in var RNA levels following increase in copy number of pTMBH. Expression levels are shown of endogenous var genes in pTMBH/C3 parasites under low (black bars) and high (grey bars) blasticin doses. (f) Representation of data depicted in (e). Total var transcript levels of pTMBH transfected C3 parasites under low (black bar) and high blasticidin doses (grey bar). The approximate copy number of the transfected episome for each drug concentration is shown in parentheses. All RNA was harvested at 18 hours post invasion (hpi). Relative copy numbers are measured with respect to the control housekeeping genes P60-seryl-tRNA synthetase (PF07_0073) using the formula 2−ΔΔCT with NF54 gDNA as the calibrator. (g) Temporal expression pattern of var, rifin, stevor, and Pfmc-2TMs during the 48 hour P. falciparum life cycle. Peak expression of var genes is at 16–18 hpi, followed by rifin at18–23 hpi, stevors at 22–32 hpi, and finally Pfmc-2TMs at 26–30 hpi. Episomal rifin, stevor, and Pfmc-2TM promoters downregulate endogenous var expression. The level of co-regulation, however, correlates with the temporal order of gene expression of these families during the 48 hour replicative cycle.