Mutant/mutation
The mutant expresses a truncated version of OVA (ovalbumin), encompassing amino acids 142 to 389 and including the well-characterized CD8+ and CD4+ T-cell epitopes, which is fused to the CSP export sequence together with an N-terminal PEXEL motif . The OVA transgene is under control of the sporozoite/liver stage specific uis4 promoter.  In addition the mutant expresses GFP under the constitutive eefa promoter

Protein (function)

Phenotype
OVA expression in sporozoites and liver stages.
expOVA largely displayed a distinct pattern on structures outside the liver stage parasite. The exported OVA molecules were always surrounded by parasite membrane material, as shown by positive staining for UIS4, a specific marker of the parasitophorous vacuole membrane (PVM). No OVA signal was detected free in the host cell cytoplasm but inside vesicles, which are often detached from the PVM.

Additional information
By comparing this mutant and a similar mutant that express OVA in the cytoplasm (RMgm-1124) evidence is presented that:
Immunization with live attenuated transgenic sporozoites revealed that antigen export was not critical for CD8 T-cell priming but enhanced CD8 T-cell proliferation in the liver. Upon transfer of antigen-specific CD8 T cells, liver-stage parasites secreting the target protein were eliminated more efficiently.

Other mutants
RMgm-1124: A simular mutant expressing OVA that is expressed in the cytoplasm of liver stages.

Click on Ovalbumin for more rodent malaria mutants expressing OVA