| 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) : 25225164
|
| 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 507cl1 (RMgm-7)
|
| Other information parent line | P.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). |
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| The mutant parasite was generated by |
| Name PI/Researcher | Akinosoglou KA, Vlachou D. |
| Name Group/Department | Department of Life Sciences |
| Name Institute | Imperial College London |
| City | London |
| Country | UK |
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| Name of the mutant parasite |
| RMgm number | RMgm-1127 |
| Principal name | Δpbgamer |
| 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 | Normal numbers of gametocytes. Exflagellation numbers are formed. Activated Δpbgamer male gametocytes produce morphologically normal and motile microgametes; however, the vast majority of them was unable to detach from the residual body of the gametocytes and remained attached to the exflagellation centers even 30 min post activation. |
| Fertilization and ookinete | (Strongly) reduced ookinete formation (18% compared to 72% in wild type) |
| Oocyst | (Strongly) reduced ookinete formation (18% compared to 72% in wild type). (Strongly) reduced oocyst formation. |
| Sporozoite | (Strongly) reduced oocyst formation. (Strongly) reduced sporozoite formation. |
| Liver stage | (Strongly) reduced sporozoite formation. However, sporozoites are infectious to mice (by mosquito-bite infection) |
| Additional remarks phenotype | Mutant/mutation
The mutant lacks expression of GAMER (gamete release protein, putative) and expresses GFP under control of the constitutive eef1a promoter
Protein (function)
GAMER encodes a small 96 amino acid protein (10.7 kD) lacking recognizable domains, as revealed by both manual annotation and three-dimensional (3D) homology modeling.
Phenotype
Normal numbers of gametocytes. Exflagellation numbers are formed. Activated Δpbgamer male gametocytes produce morphologically normal and motile microgametes; however, the vast majority of them was unable to detach from the residual body of the gametocytes and remained attached to the exflagellation centers even 30 min post activation.
Strongly) reduced ookinete formation (18% compared to 72% in wild type). (Strongly) reduced oocyst formation. (Strongly) reduced sporozoite formation. However, sporozoites are infectious to mice (by mosquito-bite infection).
The results indicate a role of GAMER in male gamete release. However, in this study evidence is presented indicating that also females have a fertility defect (through crossing experiments with fertile males of wild type parasites).
Additional information
In this study an independent mutant lacking expression of GAMER has been generated in the 2.34 wild type line of P. berghei ANKA.
RT-PCR analysis showed: expression in gametocytes, up-regulation in zygotes/ookinetes, expression in 13-day old oocysts.
Western blot analysis of mixed blood stages, gametocytes and ookinetes confirmed that GAMER is a 10 kDa polypeptide specifically produced in ookinetes. However, immunofluorescence assays (IFA) on in vitro purified (non-activated) gametocytes using GAMER antibodies revealed protein presence in the gametocyte cytoplasm, where it localizes to discrete foci possibly of vesicular nature. IFA on purified ookinetes showed a diffused signal in the ookinete cytoplasm.
Other mutants |
*RMgm-1127
