UC Riverside

Aedes aegypti serves as a vector for arboviruses such as Dengue fever, Chikungunya, Yellow Fever, and Zika. One method of controlling disease transmission is controlling mosquito population by using larvicides that act on the midgut cells. A deeper understanding of the midgut physiology of the larvae would help develop better control strategies. Larvicide first needs to cross the peritrophic matrix (PM), an acellular chitinous barrier that separates the ingested material from the midgut cells, to reach the midgut epithelium. We report for the first time, the complete PM proteome of the Aedes aegypti larvae. The mass spectrometry analysis identified 167 proteins of which 21 were chitin-binding peritrophic matrix proteins. We additionally identified 2 novel putative chitin-binding proteins that exhibit similar cysteine residues pattern and presence of glycosylation as known chitin-binding peritrophic matrix proteins. Of the proteins identified in the proteomic analysis, 17 were overexpressed and 17 were under expressed in the Cry11A toxin Resistant strain. Identification of midgut cell structure and stem cell reporter lines can be used to study tissue response to stress and damage. We developed 2 stem cell reporter lines in the larval midgut using escargot and delta promoters expressing Cyan Fluorescence Protein and Green Fluorescence Protein, respectively. Antibody was developed against the Ae. aegypti Escargot, Delta, and Prospero proteins. We also confirmed that commercially available anti-Nubbin, anti-Suppressor of Hairless, and anti-PH3 are effective in detecting enterocyte, enteroblast, and proliferating cells, respectively. Using stem cell reporter line, Delta-Gal4/UAS-eGFP, we determined that stem cells respond to environment change. The stem cell proliferation decreased and increased in response to starvation, treatment with Dextran, E. coli, and Cry11A. Identification of cell markers and protein identification of the peritrophic membrane elucidate midgut structure. This system can be used to further study midgut signaling pathways, and cell damage.