SummaryRMgm-677
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Successful modification | The parasite was generated by the genetic modification |
The mutant contains the following genetic modification(s) | Gene disruption, Introduction of a transgene |
Reference (PubMed-PMID number) |
Reference 1 (PMID number) : 22128915 Reference 2 (PMID number) : 23500072 |
MR4 number | |
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Parent parasite used to introduce the genetic modification | |
Rodent Malaria Parasite | P. berghei |
Parent strain/line | P. berghei ANKA |
Name parent line/clone | Not applicable |
Other information parent line | |
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The mutant parasite was generated by | |
Name PI/Researcher | C.Deschermeier; V.T. Heussler |
Name Group/Department | Institute of Cell Biology |
Name Institute | University of Bern |
City | Bern |
Country | Switzerland |
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Name of the mutant parasite | |
RMgm number | RMgm-677 |
Principal name | PbΔPDH-E1 |
Alternative name | |
Standardized name | |
Is the mutant parasite cloned after genetic modification | Yes |
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Phenotype | |
Asexual blood stage | Not different from wild type |
Gametocyte/Gamete | Not different from wild type |
Fertilization and ookinete | Not different from wild type |
Oocyst | Not different from wild type |
Sporozoite | Not different from wild type |
Liver stage | See 'Additional remarks phenotype'. Partly aberrant formation of mature liver-stage schizonts |
Additional remarks phenotype | Mutant/mutation In previous studies it has been shown that apicoplast-targeted proteins include enzymes of the FAS II pathway. The presence of this pathway indicates that as well as taking up lipids from its host, Plasmodium also utilizes its own de novo fatty acid synthesis. Transcriptome and proteome analyses of Plasmodium liver stages have demonstrated the expression of apicoplast-targeted enzymes involved in FAS II in liver stages, indicating an important role of de novo FAS II in the developing liver stage. It has been shown that deletion of genes encoding FAS II elongation enzymes (i.e. FabI, FabB/F, FabZ.) caused no defects in parasite blood stage replication and mosquito stage development but livers stage development was severely reduced in the FAS II-deficient parasites. Analyses of P. yoelii mutants lacking expression of PDH E1α (see below) indicate a non-essential role of PDH E1α for blood stages and mosquito stages but an important role during late liver stage development. Analysis of in vitro cultured liver stages showed significant defects in terms of growth and nuclear division. Disruption of PDH E1α showed a similar phenotype to mutants lacking FAS II elongation enzymes (i.e. FabI, FabB/f; FabZ). This suggests that in Plasmodium the sole function of PDH is to provide the acetyl-CoA necessary for de novo fatty acid synthesis. No details of the phenotype of these mutants are provided in the paper PMID: 22128915. The mutant has been used to provide evidence that a functional FAS-II pathway is necessary for lipoylation of proteins in the apicoplast of P. berghei liver stage parasites. For detailed phenotype analyses of P. yoelii parasites lacking expression PDH-E1α see the mutant RMgm-376 (and the other mutants mentioned below). PbΔPDH-E1 sporozoites infected and developed normally in HepG2 cells in comparison to wt parasites. The parasites formed an apparently normal PVM and reached the late liver stages, similar to what has been described for P. yoelii pdh-e1a knockout (PyΔPDH-E1) parasites. However, in contrast to PyΔPDH-E1 parasites, PbΔPDH-E1 parasites expressed the merozoite surface protein 1 (MSP1). MSP1 expression is induced briefly before merozoite development and the protein localises to the plasma membrane of late schizonts and later to that of the forming merozoites. Interestingly, although MSP1 was found in the plasma membrane of PbΔPDH-E1 schizonts, the staining pattern appeared diffuse rather than strictly membrane-associated and was additionally visible in the PVM, indicating a mis-localization during development, presumably directly or indirectly due to the lack of PDH-E1a. |
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Details of the target gene | |||||||||||||||||||||||||
Gene Model of Rodent Parasite | PBANKA_0923800 | ||||||||||||||||||||||||
Gene Model P. falciparum ortholog | PF3D7_1124500 | ||||||||||||||||||||||||
Gene product | pyruvate dehydrogenase E1 component subunit alpha | ||||||||||||||||||||||||
Gene product: Alternative name | PDH E1α; PDH-E1 | ||||||||||||||||||||||||
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Details of the genetic modification | |||||||||||||||||||||||||
Inducable system used | No | ||||||||||||||||||||||||
Additional remarks inducable system | |||||||||||||||||||||||||
Type of plasmid/construct used | Plasmid double cross-over | ||||||||||||||||||||||||
PlasmoGEM (Sanger) construct/vector used | No | ||||||||||||||||||||||||
Modified PlasmoGEM construct/vector used | No | ||||||||||||||||||||||||
Plasmid/construct map | |||||||||||||||||||||||||
Plasmid/construct sequence | |||||||||||||||||||||||||
Restriction sites to linearize plasmid | |||||||||||||||||||||||||
Partial or complete disruption of the gene | Partial | ||||||||||||||||||||||||
Additional remarks partial/complete disruption | |||||||||||||||||||||||||
Selectable marker used to select the mutant parasite | tgdhfr | ||||||||||||||||||||||||
Promoter of the selectable marker | pbdhfr | ||||||||||||||||||||||||
Selection (positive) procedure | pyrimethamine | ||||||||||||||||||||||||
Selection (negative) procedure | No | ||||||||||||||||||||||||
Additional remarks genetic modification | Genomic sequences flanking the ORF of P. berghei PDH-E1 (PBANKA_092380) were PCR amplified. Fragments were cloned into the vector pOB90 (Oliver Billker, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK) harboring a cassette mediating constitutive expression of cytosolic GFP using the restriction sites KpnI/ClaI and NotI/SacII. Genomic integration of this construct results in the replacement of a large part of the PbPDH-E1 ORF with a cassette mediating constitutive expression of the selection marker TgDHFR-TS and cytosolic GFP. | ||||||||||||||||||||||||
Additional remarks selection procedure | |||||||||||||||||||||||||
Primer information: Primers used for amplification of the target sequences
Primer information: Primers used for amplification of the target sequences
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Type and details of transgene | |||||||||||||||||||
Is the transgene Plasmodium derived | Transgene: not Plasmodium | ||||||||||||||||||
Transgene name | GFP | ||||||||||||||||||
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Details of the genetic modification | |||||||||||||||||||
Inducable system used | No | ||||||||||||||||||
Additional remarks inducable system | |||||||||||||||||||
Type of plasmid/construct | Plasmid double cross-over | ||||||||||||||||||
PlasmoGEM (Sanger) construct/vector used | No | ||||||||||||||||||
Modified PlasmoGEM construct/vector used | No | ||||||||||||||||||
Plasmid/construct map | |||||||||||||||||||
Plasmid/construct sequence | |||||||||||||||||||
Restriction sites to linearize plasmid | |||||||||||||||||||
Selectable marker used to select the mutant parasite | tgdhfr | ||||||||||||||||||
Promoter of the selectable marker | pbdhfr | ||||||||||||||||||
Selection (positive) procedure | pyrimethamine | ||||||||||||||||||
Selection (negative) procedure | No | ||||||||||||||||||
Additional remarks genetic modification | Genomic sequences flanking the ORF of P. berghei PDH-E1 (PBANKA_092380) were PCR amplified. Fragments were cloned into the vector pOB90 (Oliver Billker, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK) harboring a cassette mediating constitutive expression of cytosolic GFP using the restriction sites KpnI/ClaI and NotI/SacII. Genomic integration of this construct results in the replacement of a large part of the PbPDH-E1 ORF with a cassette mediating constitutive expression of the selection marker TgDHFR-TS and cytosolic GFP. | ||||||||||||||||||
Additional remarks selection procedure | |||||||||||||||||||
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Other details transgene | |||||||||||||||||||
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Promoter | |||||||||||||||||||
Gene Model of Parasite | PBANKA_0719300 | ||||||||||||||||||
Gene Model P. falciparum ortholog | PF3D7_0417200 | ||||||||||||||||||
Gene product | bifunctional dihydrofolate reductase-thymidylate synthase | ||||||||||||||||||
Gene product: Alternative name | |||||||||||||||||||
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3'-UTR | |||||||||||||||||||
Gene Model of Parasite | Not available | ||||||||||||||||||
Gene product | Not available | ||||||||||||||||||
Gene product: Alternative name | |||||||||||||||||||
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Insertion/Replacement locus | |||||||||||||||||||
Replacement / Insertion | Replacement locus | ||||||||||||||||||
Gene Model of Parasite | PBANKA_0923800 | ||||||||||||||||||
Gene product | pyruvate dehydrogenase E1 component subunit alpha | ||||||||||||||||||
Gene product: Alternative name | PDH E1α; PDH-E1 | ||||||||||||||||||
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