1. Targeted DNA methylation in pericentromeres with genome editing-based artificial DNA methyltransferase
- Author
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Yamazaki, T., Hatano, Y., Handa, T., Kato, S., Hoida, K., Yamamura, R., Fukuyama, T., Uematsu, T., Kobayashi, N., Kimura, Hiroshi, and Yamagata, K.
- Subjects
0301 basic medicine ,Embryology ,Bisulfite sequencing ,Clustered Regularly Interspaced Short Palindromic Repeats/genetics ,lcsh:Medicine ,DNA Methylation/*genetics ,Gene Editing/*methods ,Biochemistry ,Synthetic Genome Editing ,Genome Engineering ,Mice ,Heterochromatin ,Clustered Regularly Interspaced Short Palindromic Repeats ,DNA (Cytosine-5-)-Methyltransferases ,lcsh:Science ,RNA-Directed DNA Methylation ,Gene Editing ,Multidisciplinary ,DNA methylation ,Mammalian Genomics ,Crispr ,DNA (Cytosine-5-)-Methyltransferases/*metabolism ,Genomics ,Centromere/*genetics ,Chromatin ,Cell biology ,Enzymes ,Up-Regulation ,Nucleic acids ,Engineering and Technology ,Epigenetics ,Synthetic Biology ,DNA modification ,Chromatin modification ,Research Article ,Chromosome biology ,Biotechnology ,Imaging Techniques ,Epigenetic code ,Centromere ,Bioengineering ,Biology ,DNA, Satellite ,Research and Analysis Methods ,DNA methyltransferase ,Chromosomes ,Cell Line ,Up-Regulation/genetics ,03 medical and health sciences ,Fluorescence Imaging ,Epigenome editing ,Genetics ,Animals ,Embryo Implantation ,Biology and life sciences ,Base Sequence ,lcsh:R ,Embryos ,Proteins ,DNA ,Methyltransferases ,Synthetic Genomics ,DNA, Satellite/genetics ,030104 developmental biology ,Animal Genomics ,Synthetic Bioengineering ,Enzymology ,Illumina Methylation Assay ,lcsh:Q ,Gene expression ,Developmental Biology - Abstract
To study the impact of epigenetic changes on biological functions, the ability to manipulate the epigenetic status of certain genomic regions artificially could be an indispensable technology. "Epigenome editing" techniques have gradually emerged that apply TALE or CRISPR/Cas9 technologies with various effector domains isolated from epigenetic code writers or erasers such as DNA methyltransferase, 5-methylcytosine oxidase, and histone modification enzymes. Here we demonstrate that a TALE recognizing a major satellite, consisting of a repeated sequence in pericentromeres, could be fused with the bacterial CpG methyltransferase, SssI. ChIP-qPCR assays demonstrated that the fusion protein TALMaj-SssI preferentially bound to major chromosomal satellites in cultured cell lines. Then, TALMaj-SssI was expressed in fertilized mouse oocytes with hypomethylated major satellites (10-20% CpG islands). Bisulfite sequencing revealed that the DNA methylation status was increased specifically in major satellites (50-60%), but not in minor satellites or other repeat elements, such as Intracisternal A-particle (IAP) or long interspersed nuclear elements-1 (Line1) when the expression level of TALMaj-SssI is optimized in the cell. At a microscopic level, distal ends of chromosomes at the first mitotic stage were dramatically highlighted by the mCherry-tagged methyl CpG binding domain of human MBD1 (mCherry-MBD-NLS). Moreover, targeted DNA methylation to major satellites did not interfere with kinetochore function during early embryonic cleavages. Co-injection of dCas9 fused with SssI and guide RNA (gRNA) recognizing major satellite sequences enabled increment of the DNA methylation in the satellites, but a few off-target effects were also observed in minor satellites and retrotransposons. Although CRISPR can be applied instead of the TALE system, technical improvements to reduce off-target effects are required. We have demonstrated a new method of introducing DNA methylation without the need of other binding partners using the CpG methyltransferase, SssI.
- Published
- 2017