| Successful modification | The 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) : 24281719
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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
|
| Other information parent line | Two mutants are generated; one in wild type ANKA parasites and one in a GFP-expressing reference line (RMgm-7). |
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| The mutant parasite was generated by |
| Name PI/Researcher | K. E. Boysen; K. Matuschewski |
| Name Group/Department | Parasitology Unit |
| Name Institute | Max Planck Institute for Infection Biology |
| City | Berlin |
| Country | Germany |
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| Name of the mutant parasite |
| RMgm number | RMgm-970 |
| Principal name | icp(-); icp(-)-GFP |
| 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 | Not tested |
| Fertilization and ookinete | Not tested |
| Oocyst | Not different from wild type |
| Sporozoite | Only 'hemocoel-associated' sporozoites are formed. Sporozoites do not invade salivary glands. Hemocoel sporozoites show reduced gliding. Sporozoites are not infectious to hepatocytes in culture. |
| Liver stage | Sporozoites are not infectious to hepatocytes in culture and not infectious to mice (after intravenous inoculation of hemocoel sporozoites) |
| Additional remarks phenotype | Mutant/mutation
The mutant lacks expression of ICP.
Two mutants are generated; one in wild type ANKA parasites and one in a GFP-expressing reference line (RMgm-7). In this line GFP is expressed from the constitutive eef1a promoter. In the first mutant GFP is present in the icp disruption vector resulting in expression of GFP under the promoter region of icp.
Protein (function)
An endogenous cysteine protease inhibitor has been identified in P. falciparum, Pf-ICP (PF3D7_0911900; Falstatin). A recombinant Pf-ICP expressed in E. coli was shown to potently inhibit a number of host proteases by in vitro protease activity assays. Additionally, Pf-ICP also inhibited several parasite proteases in these assays, including falcipain-2 and falcipain-3, but not falcipain-1. Search the database with the P. falciparum icp gene model PF3D7_0911900 for additional mutants expressing tagged forms of ICP in rodent parasites
Phenotype
Evidence is presented that disruption of icp does not affect blood stage virulence or growth of asexual blood stages.
Mutants show normal oocyst production indicating the lack of an effect of icp disruption on gametocyte production/fertility and ookinete formation.
Only 'hemocoel-associated' sporozoites are formed. Sporozoites do not invade salivary glands. Hemocoel sporozoites show reduced gliding. Sporozoites are not infectious to hepatocytes in culture.
Additional information
Previous attempts to disrupt the icp gene were unsuccesfull. See RMgm-245, RMgm-397 and RMgm-844 for unsuccessful attempts to disrupt the P. berghei icp gene. Search the database with the P. falciparum icp gene model PF3D7_0911900 for additional mutants expressing tagged forms of ICP.
Evidence is presented for enhanced cleavage of CSP and it is proposed that ICP regulates the cysteine protease-dependent processing of CSP,
Other mutants |
*RMgm-970
