麻豆淫院

Scientists at Virginia Tech may have just made it easier to fight the world's deadliest animal: the mosquito. Only female mosquitoes bite because they need nutrients from blood to develop eggs. That drive makes them dangerous, allowing them to spread viruses such as Zika, dengue, malaria, and yellow fever, which together kill over 1 million people a year.

One promising disease control method is releasing sterile males, raised in labs, into the wild. When females mate with these sterile males, they don't produce offspring, gradually shrinking the population without relying on insecticides that harm beneficial insects.

But this approach is technically complex, labor-intensive, and costly鈥攍imiting its effectiveness and scalability.

Now, researchers have taken a major step toward solving that problem. In published in Proceedings of the National Academy of Sciences, the team has unveiled "DeMark"鈥攁 genetic system that streamlines the separation process. The method eliminates the need for manual sorting, multiple breeding lines, or foreign genetic material, making it easier to produce large batches of nonbiting male mosquitoes.

"This adds a potentially powerful new tool to global mosquito control efforts," said Austin Compton, one of the study's lead authors. "It's relatively simple and scalable."

The research was led by scientists from the Department of Biochemistry in the College of Agriculture and Life Sciences and the Fralin Life Sciences Institute.

About the DeMark system

DeMark鈥攕hort for differential elimination of marked sex chromosomes鈥攗ses genetic markers to separate out unwanted mosquitoes before they reach adulthood. What remains is a batch of nonbiting males that are not modified with any foreign genetic material.

To build the system, the researchers combined natural and lab-engineered versions of mosquito genes, or alleles, that are passed down through sex chromosomes. When inherited in certain combinations, these alleles cause some mosquitoes to die early. This built-in safeguard helps ensure that unmodified males are produced every generation and can be easily isolated based on their lack of marked sex chromosomes.

Unlike other approaches that require maintaining multiple breeding lines, DeMark works with a single breeding line, reducing both production costs and complexity.

The team also tested whether the lab-raised males could compete with wild-type mosquitoes when it came to mating. They did鈥攁 key factor for any control strategy to succeed outside the lab.

"Before these strains can be considered for potential field release, more work is needed to test their stability and competitiveness under mass-rearing and controlled semi-field conditions," said Melanie Hempel, who co-led the research as a Ph.D. student and is now a postdoctoral researcher at Virginia Tech.

Adding to the mosquito control toolbox

This study focused on Aedes aegypti, the mosquito species known for spreading Zika, dengue, chikungunya, and yellow fever. The researchers say the same approach could potentially be adapted to other species, including Anopheles gambiae, which transmits malaria.

"This approach can work hand in hand with other mosquito control strategies," said Zhijian "Jake" Tu, University Distinguished Professor and senior author of the study. "Our goal is to add to the growing toolbox of options available to fight mosquito-borne diseases in ways that make sense for different regions and communities around the world."