RMgmDB - Rodent Malaria genetically modified Parasites


Malaria parasiteP. yoelii
DisruptedGene model (rodent): PY17X_1468100; Gene model (P.falciparum): Not available; Gene product: Not available (235EBP-1; Py235EBP-1; erythrocyte binding protein 1)
Phenotype Asexual bloodstage;
Last modified: 1 December 2013, 10:42
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) : 21625465
MR4 number
Parent parasite used to introduce the genetic modification
Rodent Malaria ParasiteP. yoelii
Parent strain/lineP. y. yoelii YM
Name parent line/clone Not applicable
Other information parent lineP. yoelii YM is a virulent strain of P. yoelii
The mutant parasite was generated by
Name PI/ResearcherD. Bapat; P.R. Preiser
Name Group/DepartmentSchool of Biological Sciences
Name InstituteNanyang Technological University
Name of the mutant parasite
RMgm numberRMgm-615
Principal namePYΔpy01365(NF1); PYΔpy01365(NF2)
Alternative name
Standardized name
Is the mutant parasite cloned after genetic modificationYes
Asexual blood stageThe mutant showed a different (delayed) course of parasitemia in BALB/c mice and BALB/c mice showed a delayed death from infection. Mutant blood stages showed a restricted host cell range.
Gametocyte/GameteNot tested
Fertilization and ookineteNot tested
OocystNot tested
SporozoiteNot tested
Liver stageNot tested
Additional remarks phenotype

The mutant lacks expression of PY01365, one member of the py235 gene family.
(The gene model of P. yoelii X (XNL) is shown; however, the gene has been deleted in P. yoelii YM; sequence differences exists between members of the py235 (reticulocyte binding protein) gene family between these two laboratory strains)

Protein (function)
Of the Plasmodium erythrocyte adhesion ligand families identified to date, one of the most studied is the erythrocyte binding ligand family (EBL), which includes P. falciparum erythrocyte binding antigen (EBA)-175 and the Duffy binding protein (DBP) of P. vivax and P. knowlesi, located in the apical organelles of the merozoite.

A second group of high molecular mass adhesion proteins, which was first described in the rodent malaria parasite P. yoelii as Py235 is the reticulocyte binding-like (RBL) super family, so named because of sequence homology with the reticulocyte binding protein RBP-1 and RBP-2 of P. vivax. In P. vivax, these proteins are thought to be involved in erythrocyte selection as they bind to reticulocytes but not mature erythrocytes thereby restricting P. vivax to the invasion of reticulocytes. P. falciparum contains a small group of genes coding for proteins with similarities to Py235 and PvRBP, the PfRH family. In contrast to the PvRBP and PfRH gene families, which are small, the Py235 multigene family contains at least 11 members. Analysis of the sequences on fifteen contigs identified in the P. yoelii genome database, which represent members of the Py235 gene family (and some of which are incomplete), show they have overall conserved structural elements.
The Py235 proteins have been implicated in the selection, recognition and invasion of erythrocytes. Populations of P. yoelii asexual blood stage parasites express multiple members of the py235 gene family.The member Py235EBP-1 (encoded by the single copy gene PY01365) is recognized by mAb 25.77. In both virulent and avirulent P. yoelii parasites, PY01365 is the most abundantly transcribed Py235 member.

The mutant showed a different (delayed) course of parasitemia in BALB/c mice and BALB/c mice showed a delayed death from infection (see further 'Additional Information).

The pehenotype of an independent mutant lacking expression of  PY01365 (RMgm-405) has been reported. The phenotype of this mutant is different from the phenotype reported in this study (see 'Additional Information' below).

Additional information
Data is presented that suggests that the disruption of PY01365 leads to the increased expression of members of Py235 that are not recognized by 25.77.

A significant percentage (35-41%) of mutant schizonts stained with mAb 25.77 confirming that the protective 25.77 antibody does not only recognize a single variant of Py235.

Quantitative RT-PCR analyses indicate that disruption of PY01365 leads to a change in the overall transcription pattern of different members of Py235.

In an independent study the phenotype has been analysed from an independent P. yoelii mutant lacking expression of PY01365 (see RMgm-405).  Host cell preference (reticulocytes, normocytes), growth/multiplication rate of asexual blood stages of this mutant was NOT different from wild type parasites. Evidence is presented that there was no compensatory significant upregulation of expression of any of the other Py235 genes in the mutant parasite. For this mutant it has been suggested that that the protein PY01185  is able to fulfill the role of PY01365 by serving as an invasion ligand.

Other mutants
RMgm-405: An independent mutant lacking expression of PY01365.

  Disrupted: Mutant parasite with a disrupted gene
Details of the target gene
Gene Model of Rodent Parasite PY17X_1468100
Gene Model P. falciparum ortholog Not available
Gene productNot available
Gene product: Alternative name235EBP-1; Py235EBP-1; erythrocyte binding protein 1
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 genePartial
Additional remarks partial/complete disruption The 10178bp genomic locus MALPY00360, coding for py01365, was targeted by a double cross-over strategy. The 5' and 3' target regions are located between nucleotides 1545 - 2162 and 4729 - 5312 respectively. No information is provided on the primers used for amplification of the target regions
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
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