Scientists make male cockroaches dislike female cockroaches to sterilize them

The German cockroach or Blatella germanica is one of the most difficult pests to eradicate on the planet. That’s because they always live huddled around the corners close to people, in our homes, in our kitchens, in restaurants, and in our offices.

Cockroaches use humans to shield and eliminate their natural enemies, including birds, frogs, lizards and spiders. From there, they can freely reproduce and multiply at a tremendous rate.

Of the more than 4,600 species of cockroaches present on the planet, the reproduction rate of the German cockroach is listed in “top goods“These female cockroaches can lay an average of 30-40 eggs per litter and 6 litters per year.

After the eggs are fertilized by the male cockroach, the female cockroaches will carry the egg sac with them and protect them to increase the survival rate. Each year, a female German cockroach can give birth to more than 200 baby cockroaches. These cockroaches will mature after about a month and immediately start a new breeding cycle.

How to sterilize and destroy German cockroaches?

With an idea of ​​sterilizing German cockroaches similar to releasing sterile male mosquitoes into the environment to limit dengue fever, a team of Chinese scientists has found a way to reduce the sexual attractiveness of female cockroaches. with male cockroaches makes the male cockroaches not want to mate with them anymore.

Unlike humans, female cockroaches do not attract male cockroaches by their looks or appearance. Instead, they use the hydrocarbons in their cuticles to lure male cockroaches into a love trap.

As an insect, cockroaches coat the outside of their bodies with a rich mixture of molecules, including oily hydrocarbons that help keep them from drying out. In a study published in the journal PLOS Biology, scientists at Northwestern A&F University, Yangling, China found that a compound called 3.11-DimethylC29 was more abundant in female cockroaches than in cockroaches. male.

That’s because female cockroaches have converted this compound into female sex pheromones, or compounds that are sexually attractive to male cockroaches. When the male senses this pheromone with his antennae, he will approach the female cockroach to mate. The male will actively lift his wings to reveal a gland containing nutrients. While the female cockroach enjoys that free meal, the male will enlist her to have sex.

Like other long-chain fatty molecules, female cockroach pheromone precursors are synthesized in part by elongation of hydrocarbon chains, said Tong-Xian Liu, author of the new study and colleagues at Northwestern A&F University. shorter, through the action of an enzyme called elongase. So by blocking this elongase enzyme, Chinese scientists were able to block the female cockroach’s pheromone production.

To do that, they used RNA technology to influence protein synthesis from the German cockroach’s genes. When RNA blocked the production of an elongase called BgElo12, they found that the female cockroach’s pheromone 3,11-DimethylC29 decreased. As a result, males are less attracted to female cockroaches.

Through this experiment, Liu and colleagues also identified two genes that regulate the production of BgElo12 in cockroaches. These genes are similar to insect sex-distinguishing genes that have been detected in fruit flies.

In male cockroaches, a gene called Doublesex blocks the production of elongase, limiting the amount of pheromones produced. However, in female cockroaches, another gene, called Transformer, blocked the effect of Doublesex, turning on the gene that produces elongase.

Therefore, the study authors show that turning off the Transformer gene in female cockroaches will effectively limit pheromone production and reduce their sexual attractiveness. This can be done in so many ways and RNA interference is just one.

“Identifying this pheromone regulatory pathway is valuable because it enriches our general understanding of insect sexual behavior. Furthermore, with this important pathway in cockroaches elucidated, this could lead to better measures to control the reproduction of this pest globally.“, said Liu.

In fact, the German cockroach is the most common, difficult to kill and hated cockroach around the world. They are host to many bacteria and viruses, including the intestinal bacteria Salmonella.

German cockroaches can cause many gastrointestinal diseases such as food poisoning, dysentery, diarrhea. Cockroaches crawling on human food, dishes and utensils can infect us with pathogenic microorganisms. Cockroaches also have many allergens on their bodies, which can cause skin rashes, watery eyes, sneezing, stuffy nose and worsen asthma.

Usually, to kill German cockroaches, people often have to use toxic chemicals equivalent to pesticides or toxic compounds called cockroach baits. However, there is research that shows German cockroaches are becoming resistant to these insecticides.

Against this backdrop, the study of Liu and his colleagues proved even more valuable. If we can sterilize this cockroach with gene therapy, the world will be cleaner and humans will be a little less annoying.

Refer to Phys