Meiosis within the resulting zygotes will have no consequence, and the sporozoites produced from these zygotes will all be genetically identical to those of the original clonal infection. Again, self-fertilisation events result in zygotes which are completely homozygous, and meiosis will produce products identical to one of the original infecting clones. Meiosis in heterozygotes formed by cross-fertilisation will almost certainly produce recombinant forms of the parasite. There is also independent segregation of the 14 chromosomes into the progeny cells. The resulting sporozoites are therefore likely to be different to any of the original infecting clones.
Crossing does occur in both populations, but to differing extents.
Back to top of page Parasite-vector interactions Mosquitoes are not passive carriers of the malaria parasite. Mosquitoes mount a defensive response to any foreign body using a variety of innate immune responses. Malaria parasites can be destroyed by melanotic encapsulation, and by another non-encapsulating mechanissm, whereby ookinetes are destroyed within the mosquito gut epithelial cells. We are investigating the interaction between different clones of Plasmodium falciparum and different Anopheles vector species. This work is in its early stages, but our findings so far indicate that at least two parasite genes are involved in triggering the mosquito recognition and destruction response.