Malaria is a disease responsible for the death and suffering of millions. It has persisted in the face of billions of dollars of research on drug and vaccine development and continues to be a significant burden to public health. A vaccine with the ability to prevent transmission of the parasite through the mosquito vector would prove to be a valuable tool in any eradication strategy. These so called transmission-blocking vaccines (TBVs) take advantage of a population bottlekneck of the parasite in the mosquito and have been proven successful in blocking transmission of natural infections in the field. However, the genetic and ecological factors that influence parasite infectivity to the mosquito host remain poorly understood. Deciphering the relationship between genetic complexity of malaria infections and transmission success in the mosquito vector is therefore of paramount importance in the current context of mosquito based control strategies. The goal of this project is two-fold: (1) to identify differentially expressed transcripts in Plasmodium gametocyte isolates from Cameroon and to correlate these findings with transmission success of these gametocytes through the mosquito in the presence or absence of a transmission-blocking antibody, and (2) field test a novel high throughput approach for the Membrane Feeding Assay (MFA), the gold standard methodology for measuring successful establishment of the parasite in the mosquito. This study is part of a larger project in the Dinglasan laboratory to dissect the molecular mechanisms for alternate midgut invasion strategies by malaria parasites.