Roach genome reveals why they are so hard to kill

Avatar By Joseph Scalise | 3 years ago

A team of Chinese researchers may have finally discovered why cockroaches are so hard to get rid of, a new study published in Nature Communication reports.

While cockroaches have been humanity’s pests for thousands of years, there is a lot researchers do not know about them. In the new study, scientists shed light on the annoying insects by sequencing their genome. They analyzed the American cockroach (Periplaneta americana) and then compared it to the Australian cockroach (P. australasiae) and the smokybrown cockroach (P. fuliginosa).

That information — combined with genetic data taken from other insects — showed that the bugs have the second largest insect genome on Earth. In addition, researchers found that, while the American roach is closely related to the two other species looked at in the study, it is more closely related to certain termites than it is to the German cockroach.

That finding is important because it suggests American cockroaches could act as a blueprint that researchers could use to analyze the evolutionary relationship between roaches and termites.

Beyond such discoveries, the team also found that certain cockroach genes expanded over time, especially the ones related to chemoreception and detoxification. Chemoreception is important because it allowed the insects to develop bitter taste receptors, which gave them the ability to eat more types of food.

On the other hand, a large amount of detoxification genes helped roaches evolve resistances to different poisons and insecticides. The insects also developed specific genes that enabled them to regrow limbs and change their growth rate with age depending on the availability of food. They have a natural immunity to specific diseases as well.

“Cockroaches generally live in moist and unsanitary areas and are particularly fond of fermenting foods; thus, they have numerous opportunities to be exposed to microbes and pathogens,” the team wrote, according to NBC News.

All of the above traits show how roaches are able to live in regions all across the world. Not only do the findings shed new light on the pests, but they may also help scientists better understand how to combat them. As global warming increases, so do American cockroach populations. Scientists hope this new research could stem that rising tide.

“The harm of American cockroaches is becoming more serious with the threat of global warming,” the researchers wrote in their study, according to Gizmodo. “Our study may shed light on both controlling and making use of this insect.”