Mutant/mutation
The mutant expresses a mutated form of IMC1h. Domain 1 (“alveolin” module) of IMC1h is deleted (amino acids 103 to 306). In addition the mutated gene is C-terminally tagged with GFP (see also mutant RMgm-600 expressing full-length C-terminal GFP-tagged IMC1h)

Protein (function)
The imcb1h gene belongs to small 'family' of conserved genes that express putative membrane skeleton proteins which contain domains that share sequence homology to domains of articulins, proteins of membrane skeleton of free-living protists and show homology to the inner membrane complex protein 1 (TgIMC1) of the subpellicular network of Toxoplasma gondii tachyzoites (Khater, E.I., et al. 2004, J. Cell. Biol. 167, 425-32) . In Plasmodium eight conserved IMC1 protein family members have been identified, named IMC1a-IMC1h. Two of these, IMC1a and IMC1b, were shown to be differentially expressed in sporozoites and ookinetes, respectively, and to form part of their pellicle structures in P. berghei. IMC1a and IMC1b are structurally and functionally homologous and involved in parasite morphology, mechanical strength, gliding motility and infectivity, in accordance with their roles as membrane skeleton proteins (see also mutanst RMgm-147 and RMgm-148 lacking expression of IMC1b and IMC1a). IMC1h, is found in the pellicle of both ookinetes and sporozoites (see below) and plays a role in in morphology/shape of ookinetes and sporozoites and in motility of both stages (see mutant RMgm-601 which lacks expression of IMC1h  and mutant RMgm-602 which lacks expression of both IMC1h and IMC1b .

Multiple alignment of amino acid sequences of IMC1h orthologs from different Plasmodium species clearly reveals the presence of its single conserved “alveolin” module (domain 1), as well as a conserved carboxy-terminalmodule that is structurally unrelated (domain 2). 

Phenotype
Normal numbers of ookinetes are formed. IMC1hΔ1  ookinetes were misshapen, lacking the typical crescent shape and possessing a bulging area in the center similar to the shape of  IMC1h-KO ookinetes. IMC1hΔ1 ookinetes displayed only cytoplasmic fluorescence. Aberrant ookinete motility. Reduced oocyst production. Reduced numbers of salivary gland sporozoites. Sporozoites of parasite line IMC1h11 were misshapen possessing a bulging area, similar to IMC1h null mutant sporozoites. Reduced size of sporozoites. Aberrant sporozoite motility. Sporozoites did not infect mice (after mosquito bite).

Additional information
To study the subcellular localization of the truncated IMC1h::GFP fusion proteins in parasite lines IMC1hΔ1 and IMC1hΔ2, live ookinetes were examined for GFP fluorescence. As described previously (Tremp and Dessens, 2011), ookinetes expressing full-length IMC1h::GFP had normal shape and displayed a predominantly cortical localization of GFP fluorescence, consistent with the recuitment of IMC1h to the SPN. Both IMC1hΔ1 and IMC1hΔ12 ookinetes were misshapen, lacking the typical crescent shape and possessing a bulging area in the center similar to the shape of  IMC1h-KO ookinetes (Tremp and Dessens, 2011). This indicates that domain 1 and domain 2 are both required for IMC1h to facilitate normal ookinete morphogenesis. Subcellular localiztion of GFP fluorescence was markedly different between IMC1hΔ1 and IMC1hΔ2 ookinetes: while the GFP signal in IMC1h12 ookinetes was predominantly found at the cell cortex like in IMC1h/GFP ookinetes, IMC1hΔ1 ookinetes displayed only cytoplasmic fluorescence. These observations show that domain 1 is required for recruitment of IMC1h to the subpellicular network (SPN), a viscoelastic membrane skeleton that supports the IMC and provides tensile strength to the cell. 

Sporozoites of parasite line IMC1hΔ1 were misshapen possessing a bulging area, similar to IMC1h null mutant sporozoites (Tremp and Dessens, 2011). Like IMC1hΔ1 ookinetes, these sporozoites displayed only cytoplasmic fluorescence. 

Other mutants 
- See also mutant RMgm-600 expressing full-length C-terminal GFP-tagged IMC1h
- See mutant RMgm-4676 expressing a mutated of IMC1h. Domain 2 (arboxy-terminalmodule) of IMC1h is deleted (amino acids 397 to 504). In addition the mutated gene is C-terminally tagged with GFP