CRISPR gene editing has been the subject of many researchers around the world because of its great potential in the study human genetic disease. But more than that, scientists have high regard for this tool because it can help cure complex and debilitating diseases like dementia and cancer.
As more fine-tuning is done in the use of CRISPR gene editing, more diseases can be effectively cured. CRISPR-Cas9 has been used to accurately replace or change genes but it is mostly done in early embryos, and there is a need to increase its accuracy and ease of use. With this in mind, researchers from the University of California (UC) Berkeley have developed a new method called CRISPR-EZ (CRISPR ribonucleoprotein electroporation of zygotes) that would make gene editing easier.
"I think this technology could greatly reduce the technical barrier for this type of effort and will allow people to focus more on the science rather than be consumed by the process of genetically engineering mice," said Lin He, lead researcher and associate professor of molecular and cell biology at UC Berkeley.
Electroporation Of Zygotes vs. In Vitro Fertilization
Today, gene editing studies use in vitro fertilization to create transgenic mice. Hormones are injected to female mice to prepare them for mating. The fertilized eggs would then be injected with RNA molecules to code for the guide RNA and the Cas9 protein prior to its division. The embryos are then implanted into the mouse.
This method is expensive, time-consuming and has a low success rate. Lin He said that the percentage of successful births from these mice is only 10 to 15 percent, which necessitates collection of more than 100 embryos to create a mouse that can be used for gene editing.
To test their tool, the researchers used CRISPR-EZ in an experiment. The electroporation formed embryonic holes through jolts of electricity. These holes will served as the entry point of gene-editing molecules. Through this method, the researchers were able to successfully alter the target gene with 88 percent accuracy and successfully produce live births in about 30 to 50 percent of the fertilized eggs, primarily because of the enhanced viability of the embryos.
Because of the high success rate, the tool can also serve as a gauge to determine the desirability of the guide RNA.
"If your CRISPR-EZ doesn't work, it's not because of delivery; it's likely because your guide RNA design needs to be improved," said He.
"With CRISPR, and improvements such as CRISPR-EZ, the costs and time have both dropped at least tenfold," Cancer Research Laboratory director and UC Berkeley professor of molecular and cell biology Russell Vance said.
The study was published in the Journal of Biological Chemistry on May 5.