title: Quantification of female and male Plasmodium falciparum gametocytes by reverse transcriptase quantitative PCR.
abstract: The transmission of malaria parasites depends on the presence of sexual stages (gametocytes) in the blood, making the ratio and densities of female and male gametocytes important determinants of parasite fitness. This manuscript describes the development of reverse transcriptase quantitative PCR (RT-qPCR) assays to separately quantify mature female and male gametocytes of the human malaria parasite Plasmodium falciparum, and reveals that Pfs25 mRNA is expressed only in female gametocytes. The female (Pfs25) and male (Pfs230p) gametocyte specific RT-qPCR assays have lower detection limits of 0.3 female and 1.8 male gametocytes per microlitre of blood, respectively, making them more sensitive than microscopy. Accurate quantification of the ratio and densities of female and male gametocytes will increase understanding of P. falciparum transmission and improve the evaluation of transmission blocking interventions.
authors.affiliation: Institutes of Evolution, Immunology and Infection Research, United Kingdom. Electronic address: petra.schneider@ed.ac.uk.
authors.forename: Petra
authors.initials: P
authors.lastname: Schneider
authors.affiliation: Institutes of Evolution, Immunology and Infection Research, United Kingdom; Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom. Electronic address: sarah.reece@ed.ac.uk.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Reece
authors.affiliation: Department of Medical Microbiology, Radboud University Medical Centre, PO Box 9101, 6500HB Nijmegen, The Netherlands. Electronic address: bvanschaijk@hotmail.com.
authors.forename: Ben C L
authors.initials: BC
authors.lastname: van Schaijk
authors.affiliation: Department of Medical Microbiology, Radboud University Medical Centre, PO Box 9101, 6500HB Nijmegen, The Netherlands. Electronic address: teun.bousema@radboudumc.nl.
authors.forename: Teun
authors.initials: T
authors.lastname: Bousema
authors.affiliation: Department of Medical Microbiology, Radboud University Medical Centre, PO Box 9101, 6500HB Nijmegen, The Netherlands. Electronic address: kjerstin.lanke@radboudumc.nl.
authors.forename: Kjerstin H W
authors.initials: KH
authors.lastname: Lanke
authors.affiliation: Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, United Kingdom. Electronic address: csjmeaden@hotmail.co.uk.
authors.forename: Cora S J
authors.initials: CS
authors.lastname: Meaden
authors.affiliation: College of Medicine and Health Sciences, Sultan Qaboos University, PO Box 35, Alkhoud 123, Sultanate of Oman; Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan. Electronic address: amalgadalla@hotmail.com.
authors.forename: Amal
authors.initials: A
authors.lastname: Gadalla
authors.affiliation: Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, United Kingdom. Electronic address: lisa.ranford-cartwright@glasgow.ac.uk.
authors.forename: Lisa C
authors.initials: LC
authors.lastname: Ranford-Cartwright
authors.affiliation: College of Medicine and Health Sciences, Sultan Qaboos University, PO Box 35, Alkhoud 123, Sultanate of Oman. Electronic address: hbabiker@squ.edu.om.
authors.forename: Hamza A
authors.initials: HA
authors.lastname: Babiker
mesh_terms: D000953:Antigens, Protozoan / Q000032:analysis* / Q000235:genetics; D020869:Gene Expression Profiling; D010274:Parasitology / Q000379:methods*; D010963:Plasmodium falciparum / Q000145:classification* / Q000235:genetics*; D015800:Protozoan Proteins / Q000032:analysis* / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000953:Antigens, Protozoan; C430263:Pfs230 antigen, Plasmodium falciparum; C071284:Pfs25 protein, Plasmodium falciparum; D015800:Protozoan Proteins
keywords: Gametocyte sex ratio; Malaria; Pfs230p; Pfs25; Sex-specific quantitative PCR