| 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) : 17335919
|
| 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 2.34
|
| Other information parent line | P. berghei ANKA 2.34 is a cloned, gametocyte producer line of the ANKA strain (PubMed: PMID: 15137943). |
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| The mutant parasite was generated by |
| Name PI/Researcher | L.L. Chat; R.E. Sinden; J.T. Dessens |
| Name Group/Department | Department of Infectious and Tropical Diseases |
| Name Institute | London School of Hygiene and Tropical Medicine |
| City | London |
| Country | United Kingdom |
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| Name of the mutant parasite |
| RMgm number | RMgm-153 |
| Principal name | MC1-KO |
| 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 different from wild type |
| Fertilization and ookinete | Not different from wild type |
| Oocyst | Not different from wild type |
| Sporozoite | Not different from wild type |
| Liver stage | Not different from wild type |
| Additional remarks phenotype | Mutant/mutation
The mutant lacks expression of MC1 (metacaspase1) and expresses GFP under the control of the mc1 promoter.
Protein (function)
The MC1 protein belongs to a small 'family' of conserved genes which contain a Peptidase_C14/Caspase domain and has been identidied as a metacaspase. Caspases are cysteine proteases belonging to the Peptidase_C14 family (clan CD) with a so called Caspase Hemoglobinase Fold (CHF). Caspases are well known to play a role in apoptosis. Metacaspases are predicted CHF proteases, with paracaspases make up the caspase super-family. Metacaspases have thus far only been identified in organisms that do not possess classic caspase genes.
Phenotype
Phenotype analyses indicate a non-essential (redundant?) function of MC1 during the complete life cycle.
Analyses of GFP expression show lack of expression in asexual blood stages and male gametocytes. Female gametocytes, ookinetes, oocysts and sporozoites are GFP positive, indicating expression of MC1 in these stages.
Additional information
It has been reported that, in P. berghei, a large proportion of ookinetes undergo cell death, displaying typical apoptosis-like features such as PS translocation, nuclear condensation and DNA fragmentation. In this study apoptosis in ookinetes was studied using the following assays: Phosphatidylserine (PS) translocation was studied with fluorescein isothiocyanate (FITC)-conjugated Annexin V in conjunction with propidium iodide, by using the Annexin-FITC Apoptosis Detection Kit (Sigma–Aldrich) according to manufacturer's instructions. DNA condensation in the nucleus was assessed using acridine orange staining. DNA fragmentation was assessed by in situ terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labelling (TUNEL), by using the ApopTag® Fluorescein In Situ Apoptosis Detection Kit (Chemicon International) according to manufacturer's instructions. Caspase activation was assessed with sulphorhodamine-VAD-FMK inhibitor of caspases, by using the CaspaTag™ Pan-Caspase In Situ Assay Kit Chemicon International) according to manufacturer's instructions. The results from these apoptosis assays indicated that apoptosis-like death in ookinetes is low under the conditions tested and not significantly different between wild type and mutant ookinetes.
Other mutants |
*RMgm-153
