Sex Change Mosquito Gene Key to Dengue Eradication

Eradication of dengue may lie not in treatment but in prevention by turning female vector mosquitoes into males.

Researchers at Fralin Life Science Institute at Virginia Tech identified a genetic switch that can transform female mosquitoes into males, ridding them of the need for blood. Female mosquitoes which transmit dengue, yellow fever and chikungunya require blood for developing eggs. The researchers identified the gene called Nix in Aedes aegypti mosquitoes that causes females to transform.

"Nix provides us with exciting opportunities to harness mosquito sex in the fight against infectious diseases because maleness is the ultimate disease-refractory trait," said Zhijian Jake Tu, a professor of biochemistry in the College of Agriculture and Life Sciences and a Fralin Life Science Institute affiliate.

Researchers inserted Nix into embryos causing female mosquitoes to sprout male genitals. Removal of the gene caused male mosquitoes to turn into females.

By converting female mosquitoes into males to lower the ratio of female to male, researchers hope to control vector-borne diseases.

"We're not there yet, but the ultimate goal is to be able to establish transgenic lines that express Nix in genetic females to convert them to harmless males," said Zach Adelman, an associate professor of entomology in the College of Agriculture and Life Sciences and a Fralin Life Science affiliate.

The study has been published in Science Xpress.