Vector-borne diseases such as malaria and dengue hemorrhagic fever remain large public health burdens, and novel interventions are still needed. The emerging field of genetics-based control has seen a number of recent laboratory successes with the generation of pathogen- resistant mosquito strains as well as female-killing strains. The development of genetically modified mosquitoes still largely relies upon classical transposable element transformation, although several recent reports have made use of the site-specific integrase C31. While site- specificity allows the investigator to examine multiple transgenes in the same genetic environment, an unfortunate consequence of the attP-attB C31 system is that as a result of recombination the entire bacterial plasmid becomes integrated into the mosquito genome. This is undesirable, as many of the currently developed transgenic mosquito strains are intended as specific genetic interventions to control a targeted vector-borne pathogen where such antibiotic resistance genes could be transferred to native bacterial species. We hypothesize that recombinase-mediated cassette exchange (RMCE) can be an efficient means of delivering transgenes into important disease vector species in a site-specific manner, without the negative consequences of co-integrating bacterial sequences. As such, we propose to (1) test a panel of heterospecific lox sites for their ability to resist intramolecular recombination i cis and promote RMCE in the embryos of the dengue vector Aedes aegypti and the malaria vector Anopheles gambiae;(2) generate transgenic docking strains based on the best candidate heterospecific lox sites and determine the rate of RMCE for each using the phage P1 cre recombinase. Such an alternative system which preserves the ability to perform site-specific recombination, but avoids the integration of bacterial sequences and remains as easy to use as TE-based helper plasmids would likely be much more widely adopted, and would help to drive the field of novel genetics- based control strategies for vector-borne diseases.

Public Health Relevance

Vector-borne diseases such as malaria and dengue hemorrhagic fever remain large public health burdens, and novel interventions are still needed. Several promising control strategies based on the genetic-modification of vector species are emerging, but the process of developing such strains is slow and inefficient. The development of RMCE as we propose will accelerate efforts to deploy pathogen-resistant or female-killing mosquito strains in the fight against vector- borne diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI099843-02
Application #
8479316
Study Section
Vector Biology Study Section (VB)
Program Officer
Costero, Adriana
Project Start
2012-06-06
Project End
2014-05-31
Budget Start
2013-06-01
Budget End
2014-05-31
Support Year
2
Fiscal Year
2013
Total Cost
$199,500
Indirect Cost
$74,500
Name
Virginia Polytechnic Institute and State University
Department
None
Type
Organized Research Units
DUNS #
003137015
City
Blacksburg
State
VA
Country
United States
Zip Code
24061
Aryan, Azadeh; Myles, Kevin M; Adelman, Zach N (2014) Targeted genome editing in Aedes aegypti using TALENs. Methods 69:38-45
Aryan, Azadeh; Anderson, Michelle A E; Myles, Kevin M et al. (2013) TALEN-based gene disruption in the dengue vector Aedes aegypti. PLoS One 8:e60082