Mutant/mutation
The mutant lacks expression of the RNA binding protein Puf2.

Protein (function)
The roles of Puf (Pumilio and fem-3 mRNA binding factor) proteins are diverse yet intimately involved in the translational regulation of developmental and differentiation factors in organisms as diverse as yeast, C. elegans, Drosophila and humans. Two such proteins, Puf1 (PFE0935c) and Puf2 (PFD0825c), are known in the human malaria parasite, P. falciparum, with orthologs in all Plasmodium spp. characterized. The Plasmodium Puf proteins have the typical highly conserved organization that includes the eight tandem copies of the PUM RNA binding domain (or Pumilio Homology Domain, PHD) at the carboxyterminus of the protein and expectedly PfPuf2 was shown to bind RNA in vitro. In P. falciparum evidence has been reported for a role for Puf2 in gametocyte development although Pfpuf2 is most highly transcribed in sporozoites

Phenotype
The phenotype analyses indicate that Puf2 is not essential for blood stage development, production of gametocytes, ookinetes, oocysts and  sporozoites. However, sporozoite infectivity is affected. A significant and progressively increasing fraction of sporozoites prematurely transformed inside the salivary glands into forms that resemble young liver stages. The phenotype described for Pypuf2- sporozoites is comparable to P. berghei sporozoites that lack expression of Puf2 (see
RMgm-515, RMgm-516, RMgm-617), although also differences were detected. The phenotype analyses indicate that Puf2 regulates the transition of sporozoites into liver stage forms.

Additional information
The phenotype analyses indicate that the RNA binding protein Puf2 regulates the transition of sporozoites into liver stage forms and allows the sporozoite to remain infectious in the salivary glands while awaiting transmission, likely by stabilizing or hastening the degradation of specific mRNAs.
Through analysis of a mutant that expresses a mutated form of Puf2 (see RMgm-843) evidence is presented that only the RNA binding domain (RBD) is essential for its function.
By analysis of the location of Puf2 in sporozoites evidence is presented that Puf2 traffics to sporozoite cytosolic granules, which are negative for several markers of stress granules and P-bodies, and disappear rapidly after infection of hepatocytes.
RNAseq analyses provided evidence for a role of Puf2 in directly or indirectly maintaining the homeostasis of specific transcripts in sporozoites.

Other mutants
P. berghei mutants that lack expression of PuF2: RMgm-515, RMgm-516, RMgm-617)
RMgm-843: a P. yoelii mutant expressing a mutated form of Puf2