Virginia Tech researchers successfully used a gene disruption technique to change the eye color of a mosquito — a critical step toward new genetic strategies aimed at disrupting the transmission of diseases such as dengue fever, which kills as many as 25,000 people annually.
Zach Adelman and Kevin Myles, both associate professors of entomology in the College of Agriculture and Life Sciences and affiliated researchers with the Fralin Life Science Institute, study the transmission of vector-borne diseases and develop novel methods of control, based on genetics.
In a groundbreaking study, the scientists used a pair of engineered proteins to cut DNA in a site-specific manner to disrupt a targeted gene in the mosquito genome. The study was recently published by Science magazine, which heralded these transcription activator-like effector nuclease proteins, known as TALENs, as a major scientific breakthrough, nicknaming them “genomic cruise missiles” for their ability to allow researchers to target specific locations with great efficiency.
While TALENs have been used to edit the genomes of animal and human cell cultures, applying them to the mosquito genome is a new approach.
“With the development of this technology, our understanding of the genetic basis of many critical behaviors such as blood-feeding, host-seeking, and pathogen transmission should be greatly accelerated,” Adelman said.
To test the capability of TALENs to edit the mosquito genome, the scientists designed a pair of TALENs to target a gene whose protein product is essential to the production of eye pigmentation in Aedes aegypti — a mosquito species known for transmitting the viruses that cause dengue fever.
“To date, efforts to control dengue transmission through genetics have focused entirely on adding material to the mosquito genome. Ensuring that this added material is expressed properly and consistently has been a challenge,” Adelman said. “This technology allows us to pursue the same goals, namely, the generation of pathogen-resistant mosquitoes, through subtraction. For example, removing or altering a gene that is critical for pathogen replication.”