Epigenetic modifications are vital in regulating transcription and cell identity. DNA methylation is a key epigenetic modification that is involved in diverse biological processes including plant development and in suppressing viral fragments of DNA, called transposable elements (TEs). Changing the epigenome to build better plants and crops is an important technology that has tremendous potential for future applications. Consequently, molecular tools are needed to precisely edit the epigenome for cell design. However, first-generation molecular tools suffer based on catalytically dead CRISPR/Cas9 (dCas9) fused directly to molecular effector domains and exhibit pervasive off-target effects.
In collaboration with the Laboratory Group of Professor Jose Polo at Monash University, PEB researchers developed an improved dCas9 based epigenome editing tool to specifically change DNA methylation in the genome of cells with the highest precision reported to date. They leveraged this technology to establish that certain transcription factors were sensitive to DNA methylation in their binding sites, and that induced changes in DNA methylation at the target genes resulted in reduced transcription.
This work will fundamentally advance our understanding of transcriptional regulation and will transform our ability to control the epigenetic regulatory layers of the genome, with immense benefits for cell identity manipulation and design.
Pflueger C, Tan D, Swain T, Nguyen T, Pflueger J, Nefzger C, Polo JM, Ford E, Lister R (2018) A modular dCas9-SunTag DNMT3A epigenome editing system overcomes pervasive off-target activity of direct fusion dCas9-DNMT3A constructs. GENOME RESEARCH 28(8):1193-206.
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