Figure 4.

Quantitative reverse transcription–polymerase chain reaction (RT-PCR) used to analyze Plasmodium vivax gametocyte sex ratios. Parasite RNA was isolated by using Trizol reagent, treated with DNase, and used for RT-PCR. A, Standard curves were based on plasmid standards with the target PCR product for pvg377 (PVX_101400) associated with macrogametocytes; Pvalpha tubulin ii (ATii, PVX_098630) associated with microgametocyte; Pvs28 (PVX_111180) produced by both sexes of gametocytes; and the gametocyte gene Pvs230 (PVX_003905). B, No correlation was seen between ookinete production and the number of mature gametocytes in culture, as determined by the ratio of Pvs28 to Pvs230 by quantitative RT-PCR (qRT-PCR). No correlation could be demonstrated between ookinete production and the number of male gametocytes in culture, as determined by the ratio of ATii-to-Pvs28 by qRT-PCR. All qRT-PCR results were normalized to RNA concentration.