Mutant/mutation
The mutant expresses GFP under control of 1.2kb of the promoter region of actin II and the 3'UTR regions of the dihydrofolate synthase/folylpolyglutamate synthase gene of P. berghei. The transgene is introduced in a locus on chromosome 12 between the genes PBANKA_122210 and PBANKA_122220.

Protein (function)
Actin, a cytoskeletal protein, has many diverse functions in eukaryotic cells ranging from roles in cell motility, cell division, vesicle trafficking to functions in cell signaling and regulation of transcription. A critical property of actin is its ability to form filamentous polymers (F-actin), and a plethora of proteins are involved in the highly dynamic regulation of F-actin formation . Actins are highly conserved proteins that often exist in multiple isoforms in the eukaryotic cell and their expression is regulated both spatially and temporally during development. The number of conventional actin genes varies among eukaryotic organisms. A few single cell eukaryotes, such as Saccharomyces cerevisiae, Toxoplasma gondii, and Trypanosoma brucei encode a single actin gene, which results in lethality when targeted with gene ablation approaches. Many organisms, however, have several conventional actin genes.Apicomplexan parasites all encode one major actin isoform, here termed Actin I. All apicomplexan parasites also contain a number of actin-related and actin-like proteins. Plasmodium species species stand out in that they all encode a second conventional actin, termed Actin II.
Phenotype analyses of mutants lacking expression of Actin II indicate a major role of Actin II in the formation of male gametes (see mutant RMgm-632).

Phenotype
Phenotype analyses of mutants lacking expression of Actin II indicate a major role of Actin II in the formation of male gametes (see mutant RMgm-632).
In the mutant that expresses GFP under the control of the promoter region of actin II a GFP signal could be detected in both male and female activated gametes. After normalization for autofluorescence of non-GFP-expressing WT parasites, the fluorescence intensity of the males was about 9-fold stronger than that of females, while no signal was detected in asexual stages.

Additional information
Phenotype analyses of a mutant expressing a GFP-tagged form of Actin II (mutant RMgm-633) indicates that GFP-tagged Actin II is expressed exclusively in male gametocytes/gametes.

Other mutants
RMgm-632: A mutant lacking expression of Actin II
RMgm-633: A mutant expressing a GFP-tagged form of Actin II