Population genetics of Aedes aegypti: Sibling relatedness and candidate gene analysis

Mosquito transmitted diseases continue to threaten the health of billions of people the world over. Understanding mosquito behavior and the complex genetics controlling the ability to transmit pathogens will improve the effectiveness of vector control strategies. The mosquito Aedes aegypti is responsible for transmitting human pathogens such as the yellow fever virus as well as the dengue fever virus. A. aegypti is also a model vector for transmission of malaria and filariasis.; The first study in this dissertation describes efforts to estimate the number of sibling families of A. aegypti larvae at natural oviposition sites found on the island of Trinidad. Knowledge about the number of sibling families at egg laying sites helps predict egg-laying behavior of female mosquitoes. Estimates were made using pairwise relatedness (r _xy) calculations based on RFLP allele sharing among individual larvae. Clusters of individuals with r_xy values above the sibling discriminating value were grouped as sibling families. Sibling clusters from across oviposition containers gave molecular evidence for skip-oviposition behavior. This technique may also have application for tracking novel mosquito genotypes after being released into a wild population.; The second study is the description and linkage analysis of a novel A. aegypti scale color mutant: rubio. The mutant was discovered among adults hatched from Trinidad collected eggs. The mutation causes the normally dark colored abdominal scales to appear ivory colored. The gene (rbo) causing the mutation was mapped to chromosome 2, approximately 5.9 cM from RpL17A.; The third study is an extensive assay of polymorphisms in AeIMUC1 , an A. aegypti candidate gene for susceptibility to the avian malaria parasite Plasmodium gallinaceum. Sequence analysis of AeIMUC1 sampled from 41 individuals identified 13 haplotypes containing 6 indels and 59 SNPs. Protein alignment revealed 9 amino acid sequence haplotypes. Amino acid variants were then tested for association with the presence or absence of P. gallinaceum oocysts on the mosquito midguts. Preliminary statistical analysis showed positive association with three variants: InA, CBD1–4, and MD2. Second stage analysis, however, was unable to confirm the association.