Plasmodium falciparum sexual conversion rates can be affected by artemisinin-based treatment in naturally infected malaria patients

Patterns of Heterochromatin Transitions Linked to Changes in the Expression of Plasmodium falciparum Clonally Variant Genes

“…The main difficulty in studying P. falciparum gene expression in human infections is that only ring-stage parasites and mature gametocytes are found in the circulation, whereas all other blood stages are sequestered in different organs or tissues and therefore are not available in peripheral blood samples. Consequently, the expression of genes such as var or pfap2-g , which are active in ring stages, can be directly characterized in human blood samples ( 20 , 84 – 89 ), but the expression of genes expressed at other stages of the IDC cannot. In studies using genome-wide transcriptome analysis of patient samples, only the expression of genes expressed in rings is captured ( 16 , 84 , 90 , 91 ).…”

Number and proportion of P.falciparumgametocytes vary from acute infection to chronic parasite carriage despite unaltered sexual commitment rate

“…The observed increase could not synergize nor add to increases promoted by depletion of choline, suggesting, as DHA affects lipids, that the two effects might be the same (61). In vivo, it was recently shown that soon after ART treatment AP2G transcripts increased in many but not all patients, and data contrasted significantly between cohorts of different geographical regions, highlighting the complex regulation of sexual conversion which is likely influenced by patient, parasite characteristics and resistance status (63). Our RNAseq (S1 where true transmission investment is known (64), and Prajapati and colleagues relied on in vitro culture of sexually committed circulating parasites to define samples with higher and lower commitment rates (65).…”

“…The observed increase could not synergize nor add to increases promoted by depletion of choline, suggesting, as DHA affects lipids, that the two effects might be the same (61). In vivo, it was recently shown that soon after ART treatment AP2G transcripts increased in many but not all patients, and data contrasted significantly between cohorts of different geographical regions, highlighting the complex regulation of sexual conversion which is likely influenced by patient, parasite characteristics and resistance status (63). Our RNAseq (S1 Table) and RT-qPCR (Fig 1H and 2D) data show constant low-level expression of AP2G, the master regulator of gametocytogenesis, and equally unaltered expression of transcripts characteristic of committed schizont and early gametocytes (S1 Table and Fig 1H), suggesting that reductions in circulating Lyso-PC induced by uncomplicated clinical malaria are not capable of affecting P. falciparum sexual commitment.…”