Successful modification | The parasite was generated by the genetic modification |
The mutant contains the following genetic modification(s) |
Gene tagging
|
Reference (PubMed-PMID number) |
Reference 1 (PMID number) : 24798694 |
MR4 number |
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Parent parasite used to introduce the genetic modification |
Rodent Malaria Parasite | P. yoelii |
Parent strain/line | P. y. yoelii 17XNL |
Name parent line/clone |
RMgm-1028
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Other information parent line | This parent line expresses GFP under the control of the HSP70 promoter. The reporter gene is introduced into the silent 230p locus using the GOMO method of transfection. |
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The mutant parasite was generated by |
Name PI/Researcher | Risco-Castillo, V; Silvie, O. |
Name Group/Department | Centre d’Immunologie et des Maladies Infectieuses |
Name Institute | Faculté de Médecine Pierre et Marie Curie |
City | Paris |
Country | France |
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Name of the mutant parasite |
RMgm number | RMgm-1034 |
Principal name | RON4::mCherry |
Alternative name | |
Standardized name | |
Is the mutant parasite cloned after genetic modification | Yes |
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Phenotype |
Asexual blood stage | RON4-mCherry displayed a typical punctuate distribution in schizonts and apical localization in merozoites, indicating correct targeting to the rhoptries. No expression in gametocytes.
Normal blood stage development. |
Gametocyte/Gamete | Not tested |
Fertilization and ookinete | Not tested |
Oocyst | Not tested |
Sporozoite | RON4-mCherry is expressed in both oocyst-derived and salivary gland sporozoites, with an apical distribution consistent with rhoptry localization.
Normal numbers of sporozoites are formed that have normal infectivity in vitro (in HepG2/CD81 cells) and in vivo |
Liver stage | RON4-mCherry was not detected in 24 h liver stages but were expressed in late (72 h) liver stage parasites. Punctuate mCherry-positive structures could be distinguished over diffuse fluorescence of the parasite cytoplasm, consistent with localization to the rhoptries of forming hepatic merozoites. |
Additional remarks phenotype | Mutant/mutation
The mutant expresses a C-terminal mCherry-tagged version of RON4
Protein (function)
RON4 is a rhoptry protein. While microneme proteins are typically involved in gliding motility, adhesion to substrates and host cell recognition, rhoptry proteins have been implicated in MJ (moving junction) and PV formation as well as host cell modifications.
A recent conditional mutagenesis approach in P. berghei has shown that RON4 plays a critical role during hepatocyte infection (see RMgm-685).
Phenotype
Phenotye analyses indicate expression of RON4 in rhoptries of merozoites and sporozoites.
Additional information
In the paper evidence is presented that RON2 and RON4 are lost following rhoptry discharge during merozoite and sporozoite entry. In contrast, analyses indicate that RAP2/3 is secreted into the parasitophorous vacuole during infection. Evidence is presented that sporozoite rhoptry discharge occurs only in the presence of CD81, providing the first direct evidence for a role of CD81 during sporozoite productive invasion (the host membrane protein CD81 is required for infection of hepatocytes by P. falciparum and P. yoelii sporozoites. CD81 acts at an early stage of infection, possibly at the entry step, but the mechanisms involved are still unknown).
RON4-mCherry could be already detected in maturing liver schizonts, whereas RAP2/3-mCherry and RON2-mCherry were only observed in very late liver stages
Other mutants
See here for other RON2 mutants
See here for other RON4 mutants
See here for other RAP2/3 mutants |