Significant data implicate the Toll/imd, insulin, and TGF-? signaling pathways in the regulation of malaria parasite development in the Anopheles gambiae midgut. However, no data are available to confirm that these signaling pathways regulate parasite development in nature. We have chosen to address this issue using a SNP association mapping approach with field-collected mosquitoes from Mali and Cameroon, countries with high malaria transmission that include the geographic distribution of the most genetically diverged An. Gambiae populations yet described. We will pursue this goal through two specific aims.
The first Aim i ncludes population genetic analyses. Plasmodium falciparum infected and uninfected An. gambiae will be collected from sites in Mali and Cameroon. These sites were carefully selected to include all of the genetic diversity known to exist in the region (three molecular forms and chromosome inversion polymorphism). Mosquito samples will be grouped by site with respect to infection, molecular form and karyotype. Each mosquito will then be genotyped for roughly 384 immune signaling gene SNPs and those SNPs correlated with infection identified by association mapping. This analysis will identify SNPs putatively involved in susceptibility to P. falciparum infection. In the second Aim, selected SNPs of interest will be analyzed to determine their effects on mosquito protein function and on susceptibility to P. falciparum infection. Specifically, we will utilize immortalized An. gambiae cell lines and a combination of over expression, knock-down, and gene conversion techniques to confirm predictions of function from sequence and to prioritize SNPs for in vivo studies. For the in vivo studies, we will use two genetically distinct strains of An. gambiae, which have been genotyped for the SNPs of interest. We will use inhibitors and transfection (knockdown, O'nyong-nyong infectious clone mediated overexpression) protocols to mimic the effects of SNP-containing alleles on P. falciparum development in infected mosquitoes. Our work will take functional data from our lab and from the labs of our colleagues to examine the importance of the selected immune signaling pathways in field-collected mosquitoes. In this light, the studies proposed herein will facilitate selection of appropriate gene targets for transgenesis strategies and provide critical new insights into the population genetics of immunity in An. gambiae that to our knowledge are not currently available.
The mosquito Anopheles gambiae transmits the human malaria parasite Plasmodium falciparum in sub-Saharan Africa. Many laboratory studies have focused on how the mosquito immune system responds to and destroys these parasites, but there is little to no information on whether these responses are important in nature. Our studies will identify responses that are important in natural populations of An. gambiae with the long-term goal that this information can contribute to novel malaria control methods.
|Lee, Yoosook; Weakley, Allison M; Nieman, Catelyn C et al. (2015) A multi-detection assay for malaria transmitting mosquitoes. J Vis Exp :e52385|
|Main, Bradley J; Lee, Yoosook; Collier, Travis C et al. (2015) Complex genome evolution in Anopheles coluzzii associated with increased insecticide usage in Mali. Mol Ecol 24:5145-57|
|Norris, Laura C; Main, Bradley J; Lee, Yoosook et al. (2015) Adaptive introgression in an African malaria mosquito coincident with the increased usage of insecticide-treated bed nets. Proc Natl Acad Sci U S A 112:815-20|
|Pakpour, Nazzy; Riehle, Michael A; Luckhart, Shirley (2014) Effects of ingested vertebrate-derived factors on insect immune responses. Curr Opin Insect Sci 3:1-5|
|Lee, Yoosook; Marsden, Clare D; Nieman, Catelyn et al. (2014) A new multiplex SNP genotyping assay for detecting hybridization and introgression between the M and S molecular forms of Anopheles gambiae. Mol Ecol Resour 14:297-305|
|Drexler, Anna L; Pietri, Jose E; Pakpour, Nazzy et al. (2014) Human IGF1 regulates midgut oxidative stress and epithelial homeostasis to balance lifespan and Plasmodium falciparum resistance in Anopheles stephensi. PLoS Pathog 10:e1004231|
|Brenton, Ashley A; Souvannaseng, Lattha; Cheung, Kong et al. (2014) Engineered single nucleotide polymorphisms in the mosquito MEK docking site alter Plasmodium berghei development in Anopheles gambiae. Parasit Vectors 7:287|
|Jiang, Xiaofang; Peery, Ashley; Hall, A Brantley et al. (2014) Genome analysis of a major urban malaria vector mosquito, Anopheles stephensi. Genome Biol 15:459|
|Lee, Yoosook; Marsden, Clare D; Norris, Laura C et al. (2013) Spatiotemporal dynamics of gene flow and hybrid fitness between the M and S forms of the malaria mosquito, Anopheles gambiae. Proc Natl Acad Sci U S A 110:19854-9|
|Sanford, Michelle R; Ramsay, Steven; Cornel, Anthony J et al. (2013) A preliminary investigation of the relationship between water quality and Anopheles gambiae larval habitats in Western Cameroon. Malar J 12:225|
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