Factors affecting Plasmodium falciparum sporozoite formation in Anopheles mosquitoes

R Medicine (General);Q Science (General)

Humphreys, Georgina Sarah ; Ranford-Cartwright, Lisa

University:University of Glasgow

Department:Institute of Infection Immunity and Inflammation

关键词: Malaria, mosquitoes, Plasmodium falciparum, Anopheles, genetics, sporozoites, oocysts;   

Others  :  http://theses.gla.ac.uk/1750/1/2010humphreysphd.pdf

来源: University of Glasgow

【 摘 要 】

The relative contribution of different factors, including environmental and genetic variables, on the observed variation in genome numbers per oocyst was investigated.The variation in sporozoite numbers from two genetically different Plasmodium falciparum clones (3D7 and HB3) in Anopheles gambiae mosquitoes, and the pattern of inheritance of the phenotype was investigated.Membrane-feeding of cultured P. falciparum parasites to laboratory-reared Anopheles mosquitoes produced infected midguts for dissection.Microdissection of single oocysts from the infected midguts and the employment of polymerase chain reaction techniques allowed the products of self- and cross-fertilisation to be distinguished, and the number of genomes per oocyst to be counted.Utilising these methods allowed comparison of the relative productivity of oocysts from different genetic and environmental backgrounds.Environmental factors such as the size of the mosquito and the number of oocysts on the midgut appeared to have no effect on the number of genomes per oocyst.However the genomes per oocyst were signifcantly different when oocysts from the same clone were isolated from two different Anopheles mosquito species. The two parasite clones differed significantly in the number of genomes per oocyst they produced, and this trait was inherited in a dominant fashion.