RMgmDB - Rodent Malaria genetically modified Parasites

Summary

RMgm-5211
Malaria parasiteP. berghei
Genotype
DisruptedGene model (rodent): PBANKA_1322200; Gene model (P.falciparum): PF3D7_1458500; Gene product: spindle assembly abnormal protein 4, putative (SAS4)
Transgene
Transgene not Plasmodium: GFP (gfp-mu3)
Promoter: Gene model: PBANKA_1133300; Gene model (P.falciparum): PF3D7_1357100; Gene product: elongation factor 1-alpha (eef1a)
3'UTR: Gene model: PBANKA_0719300; Gene product: bifunctional dihydrofolate reductase-thymidylate synthase, putative (dhfr/ts)
Replacement locus: Gene model: PBANKA_0306000; Gene product: 6-cysteine protein (230p)
PhenotypeNo phenotype has been described
Last modified: 27 March 2023, 10:54
  *RMgm-5211
Successful modificationThe 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) : 35550346
MR4 number
Parent parasite used to introduce the genetic modification
Rodent Malaria ParasiteP. berghei
Parent strain/lineP. berghei ANKA
Name parent line/clone P. berghei ANKA 507cl1 (RMgm-7)
Other information parent lineP.berghei ANKA 507cl1 (RMgm-7) is a reference ANKA mutant line which expresses GFP under control of a constitutive promoter. This reference line does not contain a drug-selectable marker (PubMed: PMID: 16242190).
The mutant parasite was generated by
Name PI/ResearcherZeeshan M, Tewari R
Name Group/DepartmentSchool of Life Sciences
Name InstituteUniversity of Nottingham
CityNottingham
CountryUK
Name of the mutant parasite
RMgm numberRMgm-5211
Principal nameΔSAS4
Alternative name
Standardized name
Is the mutant parasite cloned after genetic modificationYes
Phenotype
Asexual blood stageNot different from wild type
Gametocyte/GameteNot different from wild type
Fertilization and ookineteNot different from wild type
OocystNot different from wild type
SporozoiteNot different from wild type
Liver stageNot different from wild type
Additional remarks phenotype

Mutant/mutation
The mutant lacks expression of SAS4 and expresses GFP under the constitutive ef1a promoter

Protein (function)
Centriole/basal bodies (CBBs) are associated with the microtubule organising centre (MTOC) that nucleates cilia, flagella, and centrosomes and are conserved ancestral organelles in eukaryotes. Centrioles and basal bodies (BBs) share structural features and BBs are mainly associated with flagella or cilia organisation, and extend to produce an axoneme. The canonical view of CBB biogenesis includes centriole duplication and segregation to a daughter cell during mitosis. However, in some organisms, BB biology is more diverse, for example, where the centrioles or BBs form de novo or exhibit non- canonical biogenesis, as observed in Naegleria and in some parthenogenic insect eggs.SAS4/SAS6 are ancestral core proteins involved in BB biogenesis, as predicted by phylogenetic analysis. Clear centrioles with 9 + 1 or 9 + 2 microtubules can only be seen in flagella biogenesis during male gamete formation in Plasmodium.

The centriole/basal body (CBB) is an evolutionarily conserved organelle acting as a microtubule organising centre (MTOC) to nucleate cilia, flagella, and the centrosome. SAS4/CPAP is a conserved component associated with BB biogenesis in many model flagellated cells. Plasmodium, a divergent unicellular eukaryote and causative agent of malaria, displays an atypical, closed mitosis with an MTOC (or centriolar plaque), reminiscent of an acentriolar MTOC, embedded in the nuclear membrane. Mitosis during male gamete formation is accompanied by flagella formation. There are two MTOCs in male gametocytes: the acentriolar nuclear envelope MTOC for the mitotic spindle and an outer centriolar MTOC (the basal body) that organises flagella assembly in the cytoplasm. 

Phenotype
No significant difference in male gamete formation in the Δsas4 parasite in comparison with the WT-GFP parasite. Electron micrographs of gametocytes activated for 4–5 min (early) showed no difference between Δsas4 and WT-GFP parasites. Similarly, there were no differences in electron micrographs of exflagellating gametocytes activated for 15 min (late). Zygote formation, ookinete, oocyst and sporozoite production and infectivity comparable to WT-GFP parasites.

Additional information
From the Abstract: 
'We show the coordinated location, association and assembly of SAS4 with the BB component, kinesin- 8B, but no association with the kinetochore protein, NDC80, indicating that SAS4 is part of the BB and outer centriolar MTOC in the cytoplasm. Deletion of the SAS4 gene produced no phenotype, indicating that it is not essential for either male gamete formation or parasite transmission'.

See also mutant RMgm-5153 for another mutant lacking expression of SAS4 that showed a different phenotype (Deletion of sas4 led to a 90% decrease in the formation of active exflagellation centres).

Other mutants


  Disrupted: Mutant parasite with a disrupted gene
Details of the target gene
Gene Model of Rodent Parasite PBANKA_1322200
Gene Model P. falciparum ortholog PF3D7_1458500
Gene productspindle assembly abnormal protein 4, putative
Gene product: Alternative nameSAS4
Details of the genetic modification
Inducable system usedNo
Additional remarks inducable system
Type of plasmid/construct used(Linear) plasmid 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 markereef1a
Selection (positive) procedurepyrimethamine
Selection (negative) procedureNo
Additional remarks genetic modificationThe gene-deletion targeting vector for sas4 was constructed using the pBS-DHFR plasmid, which contains polylinker sites flanking a T. gondii dhfr/ts expression cassette conferring resistance to pyrimethamine. PCR primers N1391 and N1392 were used to generate an 803 bp fragment of sas4 5′ upstream sequence from genomic DNA, which was inserted into ApaI and HindIII restriction sites upstream of the dhfr/ts cassette of pBS-DHFR. A 721 bp fragment generated with primers N1393 and N1394 from the 3′ flanking region of sas4 was then inserted downstream of the dhfr/ts cassette using EcoRI and XbaI restriction sites. The linear targeting sequence was released using ApaI/XbaI.
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
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
Sequence Primer 3
Additional information primer 3
Sequence Primer 4
Additional information primer 4
Sequence Primer 5
Additional information primer 5
Sequence Primer 6
Additional information primer 6

  Transgene: Mutant parasite expressing a transgene
Type and details of transgene
Is the transgene Plasmodium derived Transgene: not Plasmodium
Transgene nameGFP (gfp-mu3)
Details of the genetic modification
Inducable system usedNo
Additional remarks inducable system
Type of plasmid/construct(Linear) plasmid double cross-over
PlasmoGEM (Sanger) construct/vector usedNo
Modified PlasmoGEM construct/vector usedNo
Plasmid/construct map
Plasmid/construct sequence
Restriction sites to linearize plasmid
Selectable marker used to select the mutant parasitegfp (FACS)
Promoter of the selectable markereef1a
Selection (positive) procedureFACS (flowsorting)
Selection (negative) procedureNo
Additional remarks genetic modificationThe GFP gene (1 copy) has been inserted into the 230p locus (PBANKA_030600) by double cross-over integration
Additional remarks selection procedureThis reporter mutant expressing GFP does not contain a drug-selectable marker. This mutant has been selected by FACS sorting after transfection based on GFP fluorescence.
Other details transgene
Promoter
Gene Model of Parasite PBANKA_1133300
Gene Model P. falciparum ortholog PF3D7_1357100
Gene productelongation factor 1-alpha
Gene product: Alternative nameeef1a
Primer information details of the primers used for amplification of the promoter sequence  Click to view information
Primer information details of the primers used for amplification of the promoter sequence  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
3'-UTR
Gene Model of Parasite PBANKA_0719300
Gene productbifunctional dihydrofolate reductase-thymidylate synthase, putative
Gene product: Alternative namedhfr/ts
Primer information details of the primers used for amplification the 3'-UTR sequences  Click to view information
Primer information details of the primers used for amplification the 3'-UTR sequences  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
Insertion/Replacement locus
Replacement / InsertionReplacement locus
Gene Model of Parasite PBANKA_0306000
Gene product6-cysteine protein
Gene product: Alternative name230p
Primer information details of the primers used for amplification of the target sequences  Click to view information
Primer information details of the primers used for amplification of the target sequences  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
Sequence Primer 3
Additional information primer 3
Sequence Primer 4
Additional information primer 4