title: Genome wide gene amplifications and deletions in Plasmodium falciparum.
abstract: The extent to which duplications and deletions occur in the Plasmodium falciparum genome, outside of the subtelomeres, and their contribution to the virulence of the malaria parasite is not known. Here we show the presence of multiple genome wide copy number polymorphisms (CNPs) covering 82 genes, the most extensive spanning a cumulative size of 110kilobases. CNPs were identified in both laboratory strains and fresh clinical isolates using a 70-mer oligonucleotide microarray in conjunction with fluorescent in situ hybridizations and real-time quantitative PCR. The CNPs were found on all chromosomes except on chromosomes 6 and 8 and involved a total of 50 genes with increased copy numbers and 32 genes with decreased copy numbers relative to the 3D7 parasite. The genes, amplified in up to six copies, encode molecules involved in cell cycle regulation, cell division, drug resistance, erythrocyte invasion, sexual differentiation and unknown functions. These together with previous findings, suggest that the malaria parasite employs gene duplications and deletions as general strategies to enhance its survival and spread. Further analysis of the impact of discovered genetic differences and the underlying mechanisms is likely to generate a better understanding of the biology and the virulence of the malaria parasite.
authors.affiliation: Swedish Institute for Infectious Disease Control, SE-17182 Solna, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Ribacke
authors.forename: Bobo W
authors.initials: BW
authors.lastname: Mok
authors.forename: Valtteri
authors.initials: V
authors.lastname: Wirta
authors.forename: Johan
authors.initials: J
authors.lastname: Normark
authors.forename: Joakim
authors.initials: J
authors.lastname: Lundeberg
authors.forename: Fred
authors.initials: F
authors.lastname: Kironde
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Egwang
authors.forename: Peter
authors.initials: P
authors.lastname: Nilsson
authors.forename: Mats
authors.initials: M
authors.lastname: Wahlgren
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology; D005784:Gene Amplification; D017353:Gene Deletion; D018628:Gene Dosage; D005786:Gene Expression Regulation; D018503:Genome, Protozoan; D005838:Genotype; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D020411:Oligonucleotide Array Sequence Analysis; D021261:Parasitic Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D000962:Antimalarials; D015800:Protozoan Proteins