CRISPR cockroaches? A new gene-editing breakthrough makes them possible

Mutant cockroaches? It sounds like something out of a horror movie, but it could have wide-ranging applications for research into the vast biodiversity of insects.

That's because scientists from Kyoto University in Japan edited the genes of cockroaches using CRISPR-Cas9 for the first time, according to a report in ScienceDaily.

Their new study could open the door for gene-editing in a number of other insects, leading to potential applications in pest control, evolutionary biology, and other fields.

Unlocking CRISPR for 90% of insects

In fact, according to the researchers, their new method is also applicable to "90 percent of insects", according to the researchers, meaning a massive number of insects that were previously inaccessible to CRISPR researchers can now be used for research.

In a new paper published in Cell Reports Methods, the researchers outline how they produced the world's first "knockout cockroaches", meaning the first cockroaches with inactivated genes.

CRISPR is a method that has so far primarily been used to research disease treatments and prevention methods. It has been used experimentally, for example, to develop mosquitos that spread antimalaria genes. Researchers artificially introduce DNA sequences into an organism to manipulate selected locations in its genome. 

Until now, CRISPR wasn't possible on cockroaches and a number of other insects due to their embryos being inaccessible. "In a sense, insect researchers have been freed from the annoyance of egg injections," explained senior study author Takaaki Daimon of Kyoto University. "We can now edit insect genomes more freely and at will. In principle, this method should work for more than 90% of insect species."

Generational mutations

Recently, Scientists have relied on microinjecting materials into early insect embryos, which is incredibly challenging and has not been possible in a great number of species. Cockroaches, for example, shield their embryos in hard shells, making them inaccessible to scientists for these purposes.

To overcome this problem, the researchers pioneered a method that they call "direct parental" CRISPR (DIPA-CRISPR), in which they inject genetic materials straight into adult female cockroaches. In their paper, they demonstrate how injected cockroaches and beetles produced "mutated" offspring. The cockroach offspring also passed on the artificial mutations to the next generation. 

During their experiments, the researchers also produced "knockin" beetles with genes that were artificially inserted into their DNA. Their results open up a massive avenue of research into the incredibly diverse world of insects, which could have wide-ranging applications in agriculture, pest control, and even in the prevention of deadly diseases that are spread by insects.