RMgmDB - Rodent Malaria genetically modified Parasites


Malaria parasiteP. yoelii
DisruptedGene model (rodent): PBANKA_1360100; Gene model (P.falciparum): PF3D7_1347200; Gene product: nucleoside transporter 1 (NT1)
Phenotype Asexual bloodstage; Gametocyte/Gamete; Oocyst; Sporozoite;
Last modified: 12 March 2013, 17:30
Successful modificationThe parasite was generated by the genetic modification
The mutant contains the following genetic modification(s) Gene disruption
Reference (PubMed-PMID number) Reference 1 (PMID number) : 20088947
MR4 number
Parent parasite used to introduce the genetic modification
Rodent Malaria ParasiteP. yoelii
Parent strain/lineP. y. yoelii 17XNL
Name parent line/clone clone 1.1
Other information parent line17XNL is a non-lethal strain of P. yoelii
The mutant parasite was generated by
Name PI/ResearcherA.S.I. Aly; S.H.I. Kappe
Name Group/DepartmentNot applicable
Name InstituteSeattle Biomedical Research Institute, University of Washington
Name of the mutant parasite
RMgm numberRMgm-387
Principal namePynt1-
Alternative namePynt1- EP1; Pynt1- EP2
Standardized name
Is the mutant parasite cloned after genetic modificationNo
Asexual blood stageAsexual blood stages show a strongly reduced growth and multiplication. BALB/c mice infected with 50 Pynt1- did not show detectable parasitemia by thin blood smears up to 30 days p.i. Mice infected with 5000 Pynt1- became patent at day 8 p.i. with a peak average parasitemia of 2.4 % at day 12 p.i.In contrast, mice infected with 50 and 5000 wild-type BS parasites became patent at days 4 and 2 p.i., respectively, and showed average peak parasitemias of 30.2% and 36.5% at days 12 and 11 p.i., respectively.
Gametocyte/GameteIt is reported that mutant parasites show an inefficient micro- and macrogametocytogenesis and a delayed male gamete exflagellation (however, no data is shown).
Fertilization and ookineteNot tested
OocystNo oocyst formation
SporozoiteNo oocyst and sporozoite formation
Liver stageNot different from wild type
Additional remarks phenotype


Protein (function)
Plasmodium lacks the enzymatic machinery necessary for the synthesis of the purine ring de novo and rely solely on the uptake of host purines for DNA synthesis. For P. falciparum it has been demonstrated that the translocation of host purines into the parasite is mainly mediated by the plasma membrane permease PfNT1 (nucleotide transporter 1). Genetic studies demonstrated that PfNT1 plays an essential role in parasite development and replication within human erythrocytes and parasites lacking PfNT1 are conditionally lethal, growing only when purines are provided at supra-physiological concentrations (El Bissati et al., 2006, PNAS 103, 9286-91; El Bissati, 2008, Mol. Biochem. Parasitol. 161, 130-9).

Asexual blood stages show a strongly reduced growth and multiplication. Cloning of the mutant by limiting dilution was not possible (see 'Additional information').

Additional information
Currently, no P. yoelii gene model/systematic id is available from both PlasmoDB and GeneDB.
Transcriptional profiling of PyNT1 revealed a constitutive expression pattern in multiple life cycle stages of P. yoelii.

It was not possible to clone Pynt1- parasites by limited dilution using 1, 5, 10 and 50 parasites per mouse. Only after starting with 100 Pynt1- parasites as the intravenous inoculum, 15–20% of the recipient mice became patent 11–14 days post inoculation (p.i.).

Immunization of inbred and outbred mouse strains with a single low dose of Pynt1- blood stages (50-100 parasites) did not induce any patent infections and conferred complete sterile protection against lethal blood stage and sporozoite challenges. In order to investigate which type of immune responses are mediating sterile protective immunity the following mice strains were infected:  alpha–beta T cell-deficient mice (Tcra(tm1Mom)/J), which lack the alpha–beta T-cell receptor, and mature B cell-deficient mice [Igh-6(tm1Cgn)/J]. Both transgenic mouse strains are in the C57BL/6 genetic background. Both transgenic mouse strains were not protected and developed lethal parasitemias, which were first detected in blood smears at day 4 after challenge. WT C57BL/6 control mice showed complete protection. These analyses indicate that both cellular and humoral immune responses are essential for sterile protection.

Other mutants

  Disrupted: Mutant parasite with a disrupted gene
Details of the target gene
Gene Model of Rodent Parasite PBANKA_1360100
Gene Model P. falciparum ortholog PF3D7_1347200
Gene productnucleoside transporter 1
Gene product: Alternative nameNT1
Details of the genetic modification
Inducable system usedNo
Additional remarks inducable system
Type of plasmid/construct usedPlasmid double cross-over
PlasmoGEM (Sanger) construct/vector usedNo
Modified PlasmoGEM construct/vector usedNo
Plasmid/construct map
Plasmid/construct sequence
Restriction sites to linearize plasmid
Partial or complete disruption of the geneComplete
Additional remarks partial/complete disruption
Selectable marker used to select the mutant parasitetgdhfr
Promoter of the selectable markerpbdhfr
Selection (positive) procedurepyrimethamine
Selection (negative) procedureNo
Additional remarks genetic modification
Additional remarks selection procedure
Primer information: Primers used for amplification of the target sequences  Click to view information
Primer information: Primers used for amplification of the target sequences  Click to hide information
Additional information primer 1PyNT1rep1F (KpnI)
Additional information primer 2PyNT1rep2R (HindIII)
Additional information primer 3PyNT1rep3F (SpeI)
Additional information primer 4PyNT1rep4R (KspI)
Sequence Primer 5
Additional information primer 5
Sequence Primer 6
Additional information primer 6