Yellow Fever Vector
Vicki Wysocki, Ph.D., professor of chemistry at the University of Arizona, Tucson, provided a proteomics analysis of iron-related ovarian proteins from Aedes aegypti, the mosquito responsible for transmitting yellow fever and dengue fever. As the mosquito requires an iron-containing blood meal to carry out oogenesis, Dr. Wysocki and her colleagues reasoned that the iron transport proteins could be a target for vector intervention. Accordingly, they searched for iron-regulated and iron-transport proteins in the ovaries of mosquitoes raised on different diets.
This was another example of the bottoms-up approach, in which the ovaries of the insects were dissected and separated on one-dimensional gels. The bands were excised, digested with proteases, and subjected to liquid chromatography followed by mass spec analysis. The identified proteins were then surveyed on the protein database.
A large number of proteins was identified. Ferritin was one of the proteins found in the ovaries of the mosquitoes raised on the iron-containing diet, suggesting that it is upregulated in the presence of hemoglobin in artificial diets. The presence of the enzyme aconitase, known to require iron for activity in other organisms, was also detected.
“We found that proteins expressed in the ovaries of mosquitoes varied significantly depending on the diets these mosquitoes received,” explained graduate student Michelle Huang, who was involved with the study. “The proteins expressed included essential proteins performing developmental, structural, and ribosomal functions.”
Interestingly, iron-transport proteins did not pass the filtering criteria that the team had designed as part of the experimental protocol. “Some of these proteins could represent targets for population control. We are currently expanding on these experiments for more confident identification.”