Title of Project: Insecticide resistance in Aedes aegypti mosquitoes.
1. Project Description: Aedes aegypti is a container-breeding mosquito distributed in tropical and subtropical regions of the world. On a worldwide basis, A. aegypti is the most common vector of yellow fever and dengue fever flaviviruses. Dengue Fever (DF) is one of the most rapidly expanding diseases in the tropics with over 2 billion people at risk. All four serotypes of the virus are now circulating in the Americas and an estimated 100 million human infections occur annually.
Resistance to insecticides is widespread in Aedes aegypti and directly impacts our ability to control the spread of DF and other arthropod borne diseases. The concept of insecticide resistance management (IRM) treats insecticide susceptibility as a finite resource. As pesticides are applied and the target population becomes resistance, the susceptibility resource is depleted. A key assumption of IRM is that resistance alleles confer lower fitness in the absence of insecticides. Thus when a specific insecticide is discontinued, resistance will decline, and renew susceptibility. With sufficient time, during which alternative types of insecticides are used, the original insecticide can be applied again. Resistance surveillance is an essential step in IRM in providing baseline data for program planning and pesticide selection, detecting resistance at an early stage so that alternatives can be implemented and in continuously monitoring resistance.
Fundamentally, all insecticide resistance mechanisms have a biochemical basis. The two major forms of biochemical resistance are target-site resistance, which occurs when the insecticide no longer binds to its target, and detoxification enzyme-based resistance, which occurs when enhanced levels or modified activities of esterases, oxidases, or Glutathione-S-Transferases prevent the insecticide from reaching its site of action. The major goal of the proposed research is to develop molecular genetic tools for resistance surveillance in Aedes aegypti.
The student team (limited to 4) will develop and standardize bioassays and biochemical tests for monitoring insecticide resistance in Aedes aegypti. The team will hatch and rear mosquitoes, prepare them for bioassays, perform the bioassays and then conduct a series of biochemical tests for enhanced levels or modified activities of esterases, oxidases, or glutathione-S-transferases. Different populations collected from throughout Mexico and the southern U.S. will be analyzed. Individuals will prepare a written report, and the team will prepare a paper in the form of a manuscript, which will be submitted to a scientific journal for publication.
2. Faculty Mentor: Dr. William C. Black IV (wcb4@lamar.colostate.edu).
3. Location of research: Research will be conducted at the Insect Genetics Laboratories on the 4th Floor of Microbiology.
4. Expectations of the Student:
5. Pre-requisites:
6. Schedule:
Dr. Black will arrange the initial meeting to discuss the project, assign background literature reading, establish the timeline for the experiments, initiate the necessary training for the students, and introduce students to the laboratory facilities.
7. To Apply:
Student candidates for the project need to provide a letter (electronically to Dr. Black at wcb4@lamar.colostate.edu), describing why they have selected the project, what skills qualify them for the proposed work, and what their future goals are. It should not be longer then one page, and will serve as a model for future letters seeking employment, admittance to graduate or professional schools, etc.
Applications will be reviewed on a first-come first serve basis.
