Mutant/mutation
The mutant expresses GFP under control of the promoter of the ctrp gene (CSP and TRAP-related protein, CTRP))

Protein (function)
CTRP is a type 1 transmembrane protein, containing two adhesive domains in its extracellular portion, an A-domain of von Willebrand factor and a thrombospondin type I repeat (TSR, TSP).  CTRP is located in the micronemes of ookinetes. CTRP plays a role in the motility of ookinetes and invasion of midgut epithelial cells (see also mutants RMgm-140 and RMgm-141 that lack expression of CTRP).

Phenotype
The phenotype analyses indicate strong GFP expression during ookinete development and GFP is present during development of the oocysts. No GFP is detected in asexual blood stages and gametocytes. GFP expression starts a few hours after gametocyte activation. GFP expression was hardly detectable in activated female gametes that were defective in fertilisation, indicating that expression only occurs after fertilisation.

Additional information
This mutant has been used for real-time analysis of midgut invasion by the ookinete in the living mosquito as well as in explanted intact midguts. These studies permitted detailed analysis of parasite motile behaviour in the midgut and cell biological analysis of the invasion process.

Transcription of ctrp has been analysed by Northern analysis, showing detectable transcription 4h post gametocyte activation and increases in ookinetes to a maximum at 15–22 h.

Other mutants