Author: Suzanne Mansour
In no uncertain terms, CRISPR/Cas9 has revolutionized the field of genome engineering. It is easier to make desired changes to an organism’s DNA than ever before. Now, the next gen editing technology has made its mark again. An adaptation called Easi-CRISPR (Efficient additions with ssDNA inserts-CRISPR) greatly simplifies creation of transgenic mice, an essential workhorse in life sciences research.
Developed as part of a multi-institutional collaboration led by Suzanne Mansour, Ph.D., at the University of Utah, Masato Ohtsuka, Ph.D., at Tokai University, and Channabasavaiah Gurumurthy, Ph.D., at the University of Nebraska, the new method promises to greatly hasten the development of mouse models for investigating disease and health.
Recently published in Genome Biology, Easi-CRISPR overcomes a hurdle that has limited CRISPR’s utility. It has been challenging to insert long DNA sequences into genomes cut by CRISPR, a prerequisite for generating sophisticated animal models.
One such example is conditional knockouts in which a gene is altered beginning at a specific point in time rather than all throughout life. Easi-CRISPR allows for generation of both the floxed alleles and Cre insertions that are for required for the job.
What used to be a cumbersome, labor-intensive process can now be accomplished in one step. After scientists injected mice with Easi-CRISPR reagents at an early embryonic stage, up to 100 percent of the animals’ offspring contained the desired modifications. The method was highly efficient ranging from an 8.5 to 100 percent success rate for all 13 genes tested. The secret behind Easi-CRISPR is inserting single-stranded rather than double-stranded DNA.
It’s expected that the straightforward principals behind Easi-CRISPR will make it a useful and versatile tool. The method can be used to generate multiple types of mouse models and can potentially modify the genomes of livestock and other animals.
Due to an overwhelming number of email inquiries from the research community, the lead authors of this work posted another bioRxiv article that describes the detailed step-by-step protocols of Easi-CRISPR that should help with rapid adaptation to many labs.