Mutant/mutation
The mutant lacks expression of MEI2 and PALM. The palm gene has been deleted in mutant (2834cl2m1cl1; RMgm-4937) that lacks the mei2 gene and does not contain a drug selectable marker. This mutant also expresses mCherry and luciferase under constitutive promoters. 

Protein (function)
Mei2 is a member of the largest family of RNA binding proteins (RBPs) – those that contain a RNA recognition motif (RRM), a stretch of 70-90 amino acids that contain two consensus RNA-interacting motifs, RNP1 and RNP2. RRM-containing proteins are subdivided into ten separate families (RRM_1 thru RRM_10) based on shared amino acid identities between members of each family and Mei2 contains a C-terminal RRM_2, thought to be unique to fungi and plants. Plasmodium contains a single Mei2-like gene.

PALM contains an apicoplast targeting sequence and a central conserved domain that contains conserved cysteine residues. Evidence is presented that PALM plays a major role during liver stage development and evidence is presented that the lack of PALM expression affects merozoite formation in the late liver schizonts. Evidence is presented that PALM is NOT involved in the processes of apicoplast division and segregation during schizogony (see RMgm-657). 

Phenotype
Normal blood stage and mosquito stage development.
Mice intravenously infected with ∆mei2∆mei2 sporozoites have lower parasite liver loads (determined by in vivo imaging) compared to mice infected with either WT or the single gene-deletion mutant ∆mei2. 
Mice infected with 5 × 10(4) ∆mei2∆palm sporozoites did not develop blood infections. No mice developed blood infections when infected with 2-3 × 105 ∆mei2∆palm sporozoites. However, at the highest dose, 5 × 105 sporozoites, we observed blood infections in one out three mice infected with ∆mei2∆palm, with greatly prolonged prepatent periods (12-14 days). 

Additional information

Other mutants