Editing of DNA methylation using CRISPR/Cas9 and a ssDNA template in human cells.

Programmable DNA methylation is required for understanding of transcriptional regulation and elucidating gene functions. We previously reported that MMEJ-based promoter replacement enabled targeted DNA methylation in human cells. ssDNA-mediated knock-in has recently been reported to completely reduce random integrations.

A CRISPR/Cas9-based method for targeted DNA methylation enables cancer initiation in B lymphocytes.

Targeted DNA methylation is important for understanding transcriptional modulation and epigenetic diseases. Although CRISPR-Cas9 has potential for this purpose, it has not yet been successfully used to efficiently introduce DNA methylation and induce epigenetic diseases. We herein developed a new system that enables the replacement of an unmethylated promoter with a methylated promoter through microhomology-mediated end joining-based knock-in.