title: Genetic complexity of Plasmodium falciparum gametocytes isolated from the peripheral blood of treated Gambian children.
abstract: The genetic complexity of Plasmodium falciparum gametocytes isolated from Gambian children participating in a controlled trial of anti-malarial therapy was investigated. RNA and DNA were prepared from gametocyte-positive blood, which was also used in transmission experiments with Anopheles gambiae mosquitoes. Amplification by a reverse transcriptase-polymerase chain reaction (RT-PCR) of transcripts from the genes for the ring-infected erythrocyte surface antigen and the 16-kD antigen, which exhibit asexual and sexual stage-specific expression, was used to identify 30 post-treatment gametocyte isolates in which trophozoites persisted below the threshold of detection by microscopy. These included isolates from children who received sulfadoxine/pyrimethamine plus artesunate. Twenty-nine gametocyte-positive isolates that were free of subpatent trophozoites were examined further by PCR amplification of polymorphic genomic loci. We estimate that an average minimum of 2.3 genotypes occurred in these gametocyte-only isolates, and many of these were shown to be infective to mosquitoes. Thus, meiotic recombination between different genotypes is predicted to be a common event in this study area.
authors.affiliation: Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom. colin.sutherland@lshtm.ac.uk
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Sutherland
authors.forename: Ali
authors.initials: A
authors.lastname: Alloueche
authors.forename: Louisa
authors.initials: L
authors.lastname: McRobert
authors.forename: Rosalynn
authors.initials: R
authors.lastname: Ord
authors.forename: Jamie
authors.initials: J
authors.lastname: Leggat
authors.forename: Georges
authors.initials: G
authors.lastname: Snounou
authors.forename: Margaret
authors.initials: M
authors.lastname: Pinder
authors.forename: Geoffrey A T
authors.initials: GA
authors.lastname: Targett
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use*; D002648:Child; D016054:DNA, Protozoan / Q000097:blood / Q000302:isolation & purification; D004359:Drug Therapy, Combination; D004912:Erythrocytes / Q000469:parasitology; D005714:Gambia; D005838:Genotype; D005854:Germ Cells; D006801:Humans; D016778:Malaria, Falciparum / Q000097:blood* / Q000188:drug therapy; D020066:Merozoite Surface Protein 1 / Q000235:genetics; D010963:Plasmodium falciparum / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification; D016053:RNA, Protozoan / Q000097:blood / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D020066:Merozoite Surface Protein 1; D016053:RNA, Protozoan