title: Mitochondrial peroxidase TPx-2 is not essential in the blood and insect stages of Plasmodium berghei.
abstract: BACKGROUND
  Malaria parasites actively proliferate in the body of their vertebrate and insect hosts, and are subjected to the toxic effects of reactive oxygen species. The antioxidant defenses of malaria parasites are considered to play essential roles in their survival and are thus considered promising targets for intervention. We sought to identify the cellular function of thioredoxin peroxidase-2 (TPx-2), which is expressed in the mitochondria, by disrupting the TPx-2 gene (pbtpx-2) of the rodent malaria parasite Plasmodium berghei.
  
  
  RESULTS
  In three independent experiments, two disruptant populations (TPx-2 KO) and three wild-type parasite populations with pyrimethamine resistance (dhfr-ts/mt at the DHFR-TS locus) and intact pbtpx-2 (TPx-2 WT) were obtained and cloned. Null expression of TPx-2 in the KO population was confirmed by RT-PCR and Western blot analyses. The TPx-2 KO parasite developed normally in mouse erythrocytes and multiplied at a rate similar to that of the TPx-2 WT parasite during the experimental period. The peak period of gametocytemia was delayed by 1 day in the TPx-2 KO compared with that of the TPx-2 WT and the parent parasite, however, the highest gametocyte number was comparable. The number of midgut oocysts in the TPx-2 KO at 14 days post feeding was comparable to that of the TPx-2 WT.
  
  
  CONCLUSIONS
  The present finding suggests that mitochondrial Prx TPx-2 is not essential for asexual and the insect stage development of the malaria parasite.
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, 080-8555, Japan.
authors.forename: Hirono
authors.initials: H
authors.lastname: Masuda-Suganuma
authors.forename: Miho
authors.initials: M
authors.lastname: Usui
authors.forename: Shinya
authors.initials: S
authors.lastname: Fukumoto
authors.forename: Noboru
authors.initials: N
authors.lastname: Inoue
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Kawazu
mesh_terms: D000818:Animals; D001769:Blood / Q000469:parasitology*; D004912:Erythrocytes / Q000469:parasitology; D005260:Female; D055786:Gene Knockout Techniques; D020043:Genes, Essential; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics; D018512:Parasitemia / Q000469:parasitology; D054464:Peroxiredoxins / Q000235:genetics / Q000378:metabolism*; D010962:Plasmodium berghei / Q000201:enzymology* / Q000235:genetics; D013997:Time Factors; D014774:Virulence
chemical_list: D054464:Peroxiredoxins