| Successful modification | The parasite was generated by the genetic modification |
| The mutant contains the following genetic modification(s) |
Introduction of a transgene
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| Reference (PubMed-PMID number) |
Reference 1 (PMID number) : 19143588
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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 | R.R. Stanway, V.T. Heussler |
| Name Group/Department | Bernhard Nocht Institute for Tropical Medicine |
| Name Institute | Bernhard Nocht Institute for Tropical Medicine |
| City | Hamburg |
| Country | Germany |
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| Name of the mutant parasite |
| RMgm number | RMgm-267 |
| Principal name | P. berghei-GFP(apico) |
| Alternative name | |
| Standardized name | |
| Is the mutant parasite cloned after genetic modification | No |
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| Phenotype |
| Asexual blood stage | Upon nuclear division, the single elongated apicoplast of the trophozoite stage becomes branched, with branches in many, but not all, cases appearing to extend towards parasite nuclei. In mature schizonts, each forming daughter parasite again contains an individual apicoplast. |
| Gametocyte/Gamete | In female gametocytes, characterised by an elongated nucleus, the apicoplast exists as a single structure.
It is elongated, in many cases following the line of and appearing to physically contact the nucleus and in some, but not all, parasites it has one or two very short branches from the main structure. In mature male gametocytes no green-fluorescent organelle can be seen, but instead a weak cytoplasmic green fluorescence is observed. |
| Fertilization and ookinete | Ookinetes contain a single apicoplast, appearing similar in morphology to that of the female gametocyte. |
| Oocyst | During oocyst development the apicoplast becomes increasingly branched, but appears to remain as a single organelle, forming a complex and seemingly random network. Mature oocysts (containing thousands of neatly aligned daughter sporozoites) displayed thousands of distinct “lines” of green fluorescence, whose pattern matched that of sporozoites in bright field images and also that of nuclear staining patterns. |
| Sporozoite | In sporozoites a single line of apicoplast fluorescence can be seen. |
| Liver stage | The apicoplast developed from a single elongated structure in the invading sporozoite, to become increasingly branched, forming a mesh of branches, in parallel with nuclear division. The branches do not appear to follow a defined pattern and do not appear to be necessarily associated with nuclei. During the cytomere, or meroblast stage of development, the apicoplast branches change from being smooth and curved to being angular and having a concertinaed morphology. On completion of schizogony, at which point the parasitophorous vacuole contains thousands of daughter merozoites, the apicoplast was seen to have divided into thousands of individual apicoplasts, seen as small distinct spots or lines of fluorescence. |
| Additional remarks phenotype | Mutant/mutation
The mutant expresses GFP that contains a targeting sequence for the apicoplast. This sequence is the leader sequence of the acyl carrier protein (ACP, PB000543.03.0). The gfp gene is under control of the constitutive eefia promoter.
Protein (function)
Phenotype
The phenotype analyses indicate targeting of GFP to the apicoplast in all life cycle stages which allows for visualisation of the morphology and divison of the apicoplast and to analyse the effect of inhibitors on apicoplast division.
Additional information
Spinning disk microscopy confirmed that despite the highly branched nature of the apicoplast, the organelle remains as a single structure. 3D reconstructions of mature oocysts show very clearly the presence of thousands of individual apicoplasts, aligned in ring structures. Such images also show that the branched apicoplast structure has been divided, presumably into daughter sporozoites, with no residual undivided apicoplast remaining.
Other mutants |
*RMgm-267
