Mutant/mutation
The mutant lacks expression of CmanT and expresses GFP under control of the constitutive hsp70 promoter (the GFP reporter cassette is introduced into the disrupted CmanT locus)
 
Protein (function)
From the paper: 'C-Mannosylation of the thrombospondin type I repeat (TSR) domains is one of the most important factors involved in their function. It occurs on the first tryptophan of the WXXWXXC conserved motif where the tryptophan is usually surrounded by arginine or lysine forming the ligand-binding stretch of this sticky domain. It is found in its canonical or modified forms in many Plasmodium proteins. The Plasmodium proteome contains nine known canonical TSR domain-containing proteins. TSR containing proteins such as thrombospondin-like anonymous protein (TRAP), circumsporozoite protein (CSP), CSP and TRAP related protein (CTRP), and secreted protein with altered thrombospondin repeat (SPATR) have all been shown to be important for various parasite processes and life cycle stages. Here, we show that C-mannosylation catalyzing enzyme C-mannosyltransferase (CmanT) plays an essential role in malaria transmission in Plasmodium berghei.'

Phenotype
Normal, wild-type-like growth/multiplication of blood stages. Normal, wild-type-like gametocyte and ookinete production. However, ookinetes showed strongly reduced motility and motion velocity. No oocyst and sporozoite formation

Additional information
From the paper: 'CTRP was the first protein shown to be essential for ookinete motility and infectivity of mosquito midgut. Since the potential C-mannosylation motif is present in the TSR domain of CTRP and the phenotype of mutants lacking CTRP expression and the CmanT− mutants is similar, we hypothesize that C-mannosylation of the TSR domain of CTRP is one of the essential factors responsible for the CTRP mutants phenotype.'

See also the paper 'Tryptophan C-mannosylation is critical for Plasmodium falciparum transmission for mutants lacking DPY19' (PMID: 35906227). From the Abstract: 'DPY19-deficiency abolishes C-glycosylation, destabilizes members of the TRAP adhesin family and inhibits transmission to mosquitoes'. Mutants show defects in gametocyte egress, exflagellation, ookinete infectivity ond oocyst production (and mosquito infectivity). Evidence is presented that C-glycosylation is dispensable in P. falciparum salivary gland sporozoites (because O-fucosylation of essential TSR proteins like TRAP is sufficient to compensate for the absence of tryptophan C-mannosylation).

Other mutants