Schematic of expression plasmids used for transfection experiments.

<p>(A) Six promoters, two viral (CMV and SV40) and four endogenous (SmHsp70, SmActin1, Sm23, and SmCalcineurinA), were used to regulate expression of an mCherry reporter gene. These promoters were separately subcloned into vector pCI-Neo to make plasmids pEJ1175, pEJ1500, pEJ1501, pEJ1502, pEJ1503, pEJ1504, respectively. Forward arrow (a) and reverse arrow (b) represent forward oligonucleotide (a) and reverse oligonucleotide (b), used to quantify mCherry transcript levels by qRT-PCR. (B) The schistosome Actin1, CyclinB, Caspase3, and Caspase7 genes are separately regulated by the plasmid-based SmActin1 promoter. Forward and reverse arrows represent DNA oligonucleotides used for qRT-PCR analysis of each transcript (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098302#pone.0098302.s002" target="_blank">Table S2</a>). (C) Transcript levels of the schistosome Caspase 7 gene were regulated by plasmid-based SmActin1, SmHsp70, or CMV promoters. DNA oligos (c) and (d) were used for qRT-PCR analysis to measure SmCaspase7 transcript levels directed by each promoter.