| Successful modification | The parasite was generated by the genetic modification |
| The mutant contains the following genetic modification(s) |
Gene tagging,
Introduction of a transgene
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| Reference (PubMed-PMID number) |
Reference 1 (PMID number) : 28851956
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| 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
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| Other information parent line | |
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| The mutant parasite was generated by |
| Name PI/Researcher | Burda PC; Heussler VT |
| 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-4319 |
| Principal name | PbPMP1-GFP |
| Alternative name | |
| Standardized name | |
| Is the mutant parasite cloned after genetic modification | Yes |
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| Phenotype |
| Asexual blood stage | We first examined PbPMP1-GFP blood stage parasites. Here, although rather weak, the GFP signal was found to surround the cytoplasmic mCherry signal in trophozoites, merozoites and gametocytes, suggesting that PbPMP1-GFP also localizes to the parasite plasma membrane (PPM) during blood stage development. This finding was confirmed by IFA of blood stage schizonts, where PbPMP1 was co-localizing with the plasma membrane marker MSP1. |
| Gametocyte/Gamete | We first examined PbPMP1-GFP blood stage parasites. Here, although rather weak, the GFP signal was found to surround the cytoplasmic mCherry signal in trophozoites, merozoites and gametocytes, suggesting that PbPMP1-GFP also localizes to the parasite plasma membrane (PPM) during blood stage development. This finding was confirmed by IFA of blood stage schizonts, where PbPMP1 was co-localizing with the plasma membrane marker MSP1. |
| Fertilization and ookinete | PbPMP1 was also localized at the PPM of ookinetes, in which PbPMP1-GFP was additionally located in intracellular dots, possibly representing newly synthesized PbPMP1 during transport to the plasma membrane. |
| Oocyst | We analyzed the development of PbPMP1-GFP oocysts at 7, 9 and 11 days post mosquito infection. We observed a strong GFP signal in the periphery of all oocysts without any signs of invagination at day 7 post-infection, indicating that PbPMP1-GFP also labels the PPM in this parasite stage. at 9 and 11 days after the infectious blood meal, PbPMP1-GFP started to form a seemingly interconnected network within oocysts. The nuclei were thereby found to align along the newly formed membranes, at sites where subsequent sporozoite formation was initiated. Finally, PbPMP1-GFP was surrounding individual sporozoites within oocysts, which still contained portions of cytoplasmic material that had not been incorporated into forming sporozoites, these presumably being the formerly described residual bodies. |
| Sporozoite | In isolated salivary gland sporozoites and transforming sporozoites inside host HeLa cells, PbPMP1-GFP was similarly found at the parasite periphery, although the fluorescence was much weaker as compared to oocysts |
| Liver stage | IFA revealed that PbPMP1-GFP co-localized with the PPM marker MSP1 but not with exported protein 1 (EXP1), which was used to visualize the PVM. Expression of PbPMP1-GFP did not influence the development of parasites, as PbPMP1-GFP parasites showed normal numbers of sporozoites in the salivary glands and progressed normally through liver stage development. |
| Additional remarks phenotype | Mutant/mutation
The mutant expresses a C-terminal GFP-tagged version of PMP1. The pmp1 gene is under control of the constitutive eef1a promoter and is introduced into the silent c/d-rRNA gene unit. In addition the parasite expresses mCherry under the control of the eef1a promoter.
Protein (function)
P. berghei Plasma Membrane Protein 1 (PbPMP1) is a 404 amino acids protein, which is conserved among Plasmodium species and contains a predicted phospholipase C/P1-S1 nuclease domain in addition to a signal peptide and a C-terminal transmembrane domain An RNAseq study, primarily of blood stage P. berghei parasites, showed highest expression of PbPMP1 in schizont stages, in comparison to rings, trophozoites, gametocytes and ookinetes18. Furthermore, PbPMP1- derived peptides were detected in a study comparing the proteome of male and female gametocytes, indicating expression at this stage.
A mutant lacking expression of PMP1 shows normal development throughout the complete life cycle (see RMgm-4320).
Phenotype
See also mutant RMgm-4320 which lacks expression of PMP1 and shows normal development throughout the complete life cycle.
PMP1 was located at the parasite plasma membrane (PPM) in all life cycle stages (see above for more details).
Additional information
Other mutants
RMgm-4320 - A mutant lacking expression of PMP1 and expressing mCherry under the control of the P. berghei hsp70 promoter
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*RMgm-4319
