The microneme proteins CTRP and SOAP are not essential for Plasmodium berghei ookinete to oocyst transformation in vitro in a cell free system.
BACKGROUND
Two Plasmodium berghei ookinete micronemal proteins, circumsporozoite and TRAP related protein (CTRP) and secreted ookinete adhesive protein (SOAP) both interact with the basal lamina component laminin. Following gene disruption studies it has been proposed that, apart from their role in motility, these proteins may be required for interactions leading to ookinete-to-oocyst transformation.


METHODS
CTRP and SOAP null mutant P. berghei ookinetes were compared to P. berghei ANKA wild-type for their ability to transform and grow in vitro. To confirm in vitro findings for P. berghei CTRP-KO ookinetes were injected into the haemocoel of Anopheles gambiae female mosquitoes.


RESULTS
Transformation, growth, and viability were comparable for the gene disrupted and wild-type parasites. P. berghei CTRP-KO ookinetes were able to transform into oocysts in the haemocoel of An. gambiae mosquitoes.


CONCLUSIONS
Neither CTRP nor SOAP is required for parasite transformation in vitro. By-passing the midgut lumen allows for the transformation of P. berghei CTRP-KO ookinetes suggesting that it is not required for transformation in vivo.
Nacer
Adéla
A
Centre for Applied Entomology and Parasitology, Institute of Science and Technology in Medicine, School of Life Sciences, Keele University, Staffordshire, ST5 5BG, UK. a.m.l.nacer@biol.keele.ac.uk
Underhill
Ann
A
Hurd
Hilary
H
D000818:Animals; D000852:Anopheles / Q000469:parasitology; D002470:Cell Survival; D017353:Gene Deletion; D006458:Hemolymph / Q000469:parasitology; D008297:Male; D051379:Mice; D016254:Mutagenesis, Insertional; D033661:Oocysts / Q000254:growth & development*; D010962:Plasmodium berghei / Q000235:genetics / Q000254:growth & development*; D015800:Protozoan Proteins / Q000235:genetics / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology*
C120163:PbCTRP protein, Plasmodium; D015800:Protozoan Proteins; D011956:Receptors, Cell Surface; C482106:secreted ookinete adhesive protein, Plasmodium