Back to search resultsSummaryRMgm-599
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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) : 22342550 |
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 | P. berghei ANKA 676m1cl1 (RMgm-29) |
Other information parent line | 676m1cl1 (RMgm-29) is a reference ANKA mutant line which expresses GFP-luciferase under control of a constitutive promoter. This reference line does not contain a drug-selectable marker (PubMed: PMID: 16242190). |
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The mutant parasite was generated by | |
Name PI/Researcher | T. Annoura; C.J. Janse; S.M. Khan |
Name Group/Department | Leiden Malaria Research Group |
Name Institute | Leiden University Medical Center |
City | Leiden |
Country | The Netherlands |
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Name of the mutant parasite | |
RMgm number | RMgm-599 |
Principal name | 1704cl1 |
Alternative name | ∆fabb/f |
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 | Normal numbers of salivary gland sporozoites are formed. Sporozoites have a reduced infectivity to mice as shown by a significant delay of blood infections (prolonged prepatent period) after intravenous inoculation of sporozoites. |
Liver stage | Normal numbers of salivary gland sporozoites are formed. Sporozoites have a reduced infectivity to mice as shown by a significant delay of blood infections (prolonged prepatent period) after intravenous inoculation of sporozoites. Sporozoites showed normal cell traversal, hepatocyte invasion rates and initial stages of intrahepatic development. The formation of merozoites within the liver schizonts was affected (see 'Additional information'). Intravenous injection of 50.000 sporozoites resulted in breakthrough blood infections in the majority (80–100%) of BALB/c mice. All C57BL/6 mice developed a blood stage infection when infected with 50.000 sporozoites. The blood infections show a prolonged prepatency period of 1–2 days as compared to WT parasites. Assuming a P. berghei blood stage multiplication rate of 10× per 24 h this delay to patency indicates a 90–99% reduction in the production and/or infectivity of the Δfabb/f exo-erythrocytic merozoites. |
Additional remarks phenotype | Mutant/mutation FAS-II enzymes have been localized to the apicoplast, a nonphotosynthetic plastid organelle of cyanobacterial origin. FAS-II requires acetyl-Coenzyme A (CoA), which can be converted from pyruvate by the pyruvate dehydrogenase complex. Acetyl-CoA carboxylase converts acetyl-CoA to malonyl-CoA, which is tethered to an acyl carrier protein (ACP) by malonyl-CoA:ACP transacylase (FabD). This produces malonyl-ACP, which, in conjunction with acetyl-CoA, is acted upon by β-ketoacyl-ACP synthase III (Fab H) to form β-ketoacyl-ACP. This precursor enters the FAS-II elongation cycle, mediated by FabB/F (β-ketoacyl-acyl-carrier-protein (ACP) synthase), FabG (β-ketoacyl-ACP reductase), FabZ/A (β-hydroxyacyl-ACP dehydratase), and FabI (trans-2-enoyl-ACP reductase). These four FAS-II enzymes iteratively catalyze the addition of two carbon chains to a growing fatty acyl carbon chain via condensation, reduction, dehydration, and reduction steps, respectively. Phenotype blood stage multiplication rate of 10× per 24 h this delay to patency indicates a 90–99% reduction in the production and/or infectivity of the Δfabb/f exo-erythrocytic merozoites. Additional information parasites lacking expression of FabB/F (RMgm-183), where schizonts show clear signs of degeneration and absence of MSP1 expression. Other mutants RMgm-598: An independent P. berghei mutant lacking expression of FabB/F. |
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Details of the target gene | |||||||||||||||||||||||||
Gene Model of Rodent Parasite | PBANKA_1125100 | ||||||||||||||||||||||||
Gene Model P. falciparum ortholog | PF3D7_0626300 | ||||||||||||||||||||||||
Gene product | 3-oxoacyl-acyl-carrier protein synthase I/II | ||||||||||||||||||||||||
Gene product: Alternative name | FabB/F | ||||||||||||||||||||||||
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Details of the genetic modification | |||||||||||||||||||||||||
Inducable system used | No | ||||||||||||||||||||||||
Additional remarks inducable system | |||||||||||||||||||||||||
Type of plasmid/construct used | (Linear) PCR construct 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 | Asp718, ScaI | ||||||||||||||||||||||||
Partial or complete disruption of the gene | Complete | ||||||||||||||||||||||||
Additional remarks partial/complete disruption | |||||||||||||||||||||||||
Selectable marker used to select the mutant parasite | hdhfr | ||||||||||||||||||||||||
Promoter of the selectable marker | pbdhfr | ||||||||||||||||||||||||
Selection (positive) procedure | pyrimethamine | ||||||||||||||||||||||||
Selection (negative) procedure | No | ||||||||||||||||||||||||
Additional remarks genetic modification | The mutant was generated by disruption of the gene using a linear construct that was generated using a 2-step, anchor tagging PCR method (for primer details see below). The 5’- and 3’ targeting regions of the gene were PCR amplified from genomic DNA using primer pairs 1&2 and 3&4. Primers 2 and 3 have 5’-terminal extensions homologues to the hDHFR selectable marker cassette. Primers 1 and 4 both have a 5’-terminal overhang with an anchor-tag which serves as a primer site in the 2nd PCR reaction. The target fragments from the first PCR reaction were annealed to either side of the selectable marker cassette by PCR with anchor-tag primers 5 and 6, resulting in the 2nd PCR product. The hDHFR selectable marker cassette used in this reaction was digested from pL0040 using restriction enzymes XhoI and NotI. pL0040 is available from The Leiden Malaria Research Group. To remove the anchor-tags from the final KO construct, and to eliminate contaminating pL0040, the 2nd PCR product was digested with Asp718/ScaI and DpnI respectively. DpnI only cuts methylated plasmid DNA but not the PCR product. | ||||||||||||||||||||||||
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 | A fusion of GFP (gfp-mu3) and Luciferase Firefly (LucIAV) | ||||||||||||||||||
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Details of the genetic modification | |||||||||||||||||||
Inducable system used | No | ||||||||||||||||||
Additional remarks inducable system | |||||||||||||||||||
Type of plasmid/construct | (Linear) plasmid double cross-over | ||||||||||||||||||
PlasmoGEM (Sanger) construct/vector used | No | ||||||||||||||||||
Modified PlasmoGEM construct/vector used | No | ||||||||||||||||||
Plasmid/construct map | |||||||||||||||||||
Plasmid/construct sequence |
1 aattcactgg ccgtcgtttt acaacgtcgt gactgggaaa accctggcgt tacccaactt
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Restriction sites to linearize plasmid | ApaI, SacII | ||||||||||||||||||
Selectable marker used to select the mutant parasite | gfp (FACS) | ||||||||||||||||||
Promoter of the selectable marker | eef1a | ||||||||||||||||||
Selection (positive) procedure | FACS (flowsorting) | ||||||||||||||||||
Selection (negative) procedure | No | ||||||||||||||||||
Additional remarks genetic modification | The GFP-Luciferase gene (1 copy) has been inserted into the 230p locus (PBANKA_030600) by double cross-over integration. | ||||||||||||||||||
Additional remarks selection procedure | |||||||||||||||||||
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Other details transgene | |||||||||||||||||||
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Promoter | |||||||||||||||||||
Gene Model of Parasite | PBANKA_1133300 | ||||||||||||||||||
Gene Model P. falciparum ortholog | PF3D7_1357100 | ||||||||||||||||||
Gene product | elongation factor 1-alpha | ||||||||||||||||||
Gene product: Alternative name | eef1a | ||||||||||||||||||
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3'-UTR | |||||||||||||||||||
Gene Model of Parasite | PBANKA_0719300 | ||||||||||||||||||
Gene product | bifunctional dihydrofolate reductase-thymidylate synthase, putative | ||||||||||||||||||
Gene product: Alternative name | dhfr/ts | ||||||||||||||||||
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Insertion/Replacement locus | |||||||||||||||||||
Replacement / Insertion | Replacement locus | ||||||||||||||||||
Gene Model of Parasite | PBANKA_0306000 | ||||||||||||||||||
Gene product | 6-cysteine protein | ||||||||||||||||||
Gene product: Alternative name | 230p | ||||||||||||||||||
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