With the recent discovery of the first male-determining genetic factor in mosquitoes and our recent advancements in gene-editing capabilities thanks to the CRISPR-Cas9 system, a team of Virginia Tech researchers explores the possibility of manipulating mosquito populations from the blood-sucking females toward the harmless, nectar-feeding males in order to combat the spread of mosquito-borne diseases such as Zika, dengue fever, malaria and yellow fever.
"We are at a turning point both in our understanding of how mosquitoes determine whether to become a male (a good choice for us) or a female (trouble for us), as well as our ability to permanently modify wild populations using gene drive techniques," Zach Adelman, coauthor of the paper, said in a press release.
Currently, transgenic mosquitoes are the most promising technique for the control of dengue fever and other mosquito-borne diseases, as it has been successful in the few areas is has been tested. However, due to its expensive and impractical nature it is not ideal for the long-term control of mosquito-borne diseases. Alternatively, driving the maleness genes using the CRISPR-Cas9 system is an easy, efficient way of introducing mutations to any genomic sites on a variety of organisms, including mosquitoes.
Last May, a study coauthored by Zhijian Tu, who coauthored the current paper with Adelman, discovered the first male-determining sex factor, Nix, in mosquitoes.
"This discovery sets the stage for future efforts to leverage the CRISPR-Cas9 system to drive maleness genes such as Nix into mosquito populations, thereby converting females into males or simply killing females," Tu said. "Either outcome would help to reduce mosquito populations and improve sex separation procedures, which are required in any genetic strategy to prevent the accidental release of disease-transmitting females into wild populations."
Despite the promise shown by this technique, many questions need to be answered before it is used on a larger scale, including how Nix controls sex determination in mosquitoes as well as the effectiveness and long-term stability of the technique.
The findings were published in the Feb. 17 issue of Trends in Parasitology.
