Mutant/mutation
The mutant lacks expression of PbSR (P. berghei Scavenger Receptor-like protein; PSLAP; LAP1; LCCL domain containing protein CCp3).

Protein (function)
The pbsr gene is a member of a small conserved gene family, encoding proteins with multiple adhesive domains, for example a Lgl1 (LCCL)-lectin adhesive domain. In P. falciparum the LCCL domain-containing proteins are termed PfCCp's. PbSR contains four LCCL domains; a LH2 (lipoxygenase homology 2) domain; two SR (scavenger receptor cysteine-rich) domains and a PTX/LamG (pentraxin/laminin-G) domain related to concanavalin A-like module.  

Phenotype
The phenotype analyses indicate a role in the formation of sporozoites in the oocyst (see also Additional information).

Additional information
In another study (Raine, J.D. et al., 2007, PloS Pathogens 3, e30) it has been shown that crossings of the mutant females with wild type males did not rescue the formation of sporozoites. In contrast, crossing of the mutant males with wild type females resulted in wild type production of sporozoites that were infectious to C57BL/6 mice.
The lack of rescue of the ∆pbsr mutant phenotype by crossing of mutant females with wild type males is suggestive of a role of PbSR within a few hours after fertilisation.
The protein is expressed in female gametocytes and in ookinetes. In the ookinetes PbSR is associated with crystalloids, transient organelles that form in developing ookinetes and disappear after ookinete-to-oocyst transition (Carter, V. et al., 2008, Mol. Microbiol. 68, 1560-1569; RMgm-116). Plasmodium crystalloids are cytoplasmic aggregations of closely packed spherical particles 25–35 nm in diameter. In an independent mutant lacking expression of PbSR (RMgm-114) a few oocysts formed sporozoites, which might indicate that PbSR is not essential for sporozoite formation in mosquitoes, but that without functional PbSR sporulation levels are highly reduced. In this mutant no salivary gland sporozoites were detected. Interestingly, sporulation in oocysts of mutants in in vitro cultures of oocysts was comparable to that in wild type oocysts, which might suggest that the function of PbSR is influenced by mosquito factors.

A P. falciparum mutant has been generated that lacks expression of CCp3 (PbSR). This mutant showed 'normal' sporozoite formation (sporulation) within oocysts in Anopheles freeborni. Howver, no hemocoel or salivary gland sporozoites were detected (Pradel G. et al., 2004, J. Exp. Med 199, 1533-1544).

Other mutants
RMgm-114: An independent mutant lacking PbSR
RMgm-115: A mutant containing a mutated form of PbSR
RMgm-116: A mutant expressing a GFP- and mCherry-tagged version of PbSR
RMgm-117: A mutant expressing a GFP- tagged version of PbSR