Since its invention, CRISPR-Cas9 has been hailed as the answer to many of our genetic worries. The gene-editing tool has made strides in many areas of research and treatment of diseases, including sickle cell anemia, high cholesterol levels, and the rare eye disease Leber congenital amaurosis.

And its benefits extend beyond humankind.

CRISPR in cockroaches 

In a first, CRISPR has been used for genetic editing of cockroach DNA. The simple and effective technique, termed “direct parental” CRISPR (DIPA-CRISPR), involves the injection of molecules into pregnant female adults to impact the genome of their developing eggs.

Due to the complex reproductive cycles of cockroaches and insects in general, the usual CRISPR technique of embryo injections is severely limiting, however, this revolutionary method bypasses this previous challenge. “In a sense, insect researchers have been freed from the annoyance of egg injections,” says senior 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.”

The team managed to overcome these problems by inserting molecules called Cas9 ribonucleoproteins (RNPs) into the main body of a female cockroach which introduce mutations into the eggs. Currently, the technique has a low efficiency of 22 percent in cockroaches and 50 percent in beetles, though the team is continuing research to improve the method.

Why is this research useful?

The ability to carry out DIPA-CRISPR in two animals so evolutionarily distant shows the technique’s potential for broad use. Despite its current limitations, the method is accessible, highly practical, and could be easily implemented in many laboratories. Moreover, this injection method requires minimal equipment and eliminates time-consuming steps in the procedure.

”By improving the DIPA-CRISPR method and making it even more efficient and versatile, we may be able to enable genome editing in almost all of the more than 1.5 million species of insects, opening up a future in which we can fully utilize the amazing biological functions of insects,” Daimon says.

They continue: ”In principle, it may be also possible that other arthropods could be genome-edited using a similar approach. These include medical and agricultural pests such as mites and ticks and important fishery resources such as shrimp and crabs.”

Source study: Cell Reports Methods – DIPA-CRISPR is a simple and accessible method for insect gene editing