Targeted in vivo epigenome editing of H3K27me3

• Published in: Epigenetics & chromatin 2019-03, Vol.12 (1), p.17-17, Article 17
• Main Authors: Fukushima, Hiroto S, Takeda, Hiroyuki, Nakamura, Ryohei
• Format: Article
• Language: English
• Subjects: Animals; Bioinformatics; CRISPR; dCas9; Deoxyribonucleic acid; DNA; DNA methylation; Embryo, Nonmammalian; Embryos; Enhancer of Zeste Homolog 2 Protein - metabolism; Enzymes; Epigenesis, Genetic; Epigenetic inheritance; Epigenetics; Epigenome editing; Fish Proteins - metabolism; Gene Editing - methods; Gene expression; Gene Expression Regulation, Developmental; Gene loci; Gene regulation; Genes; Genetic engineering; Genomes; Genomics; H3K27me3; High-throughput screening (Biochemical assaying); Histone modification; Histones - metabolism; Insects; Medaka; Messenger RNA; Methylation; Methyltransferase; Mutation; Next-generation sequencing; Organisms; Oryzias - genetics; Oryzias - metabolism; Oryzias latipes; Protein Processing, Post-Translational; RNA; RNA, Guide, CRISPR-Cas Systems; Technology; Transcription; Transcription (Genetics); Transcriptional regulation; Transferases
• ISSN: 1756-8935; 1756-8935
• DOI: 10.1186/s13072-019-0263-z

Epigenetic modifications have a central role in transcriptional regulation. While several studies using next-generation sequencing have revealed genome-wide associations between epigenetic modifications and transcriptional states, a direct causal relationship at specific genomic loci has not been fully demonstrated, due to a lack of technology for targeted manipulation of epigenetic modifications. Recently, epigenome editing techniques based on the CRISPR-Cas9 system have been reported to directly manipulate specific modifications at precise genomic regions. However, the number of editable modifications as well as studies applying these techniques in vivo is still limited. Here, we report direct modification of the epigenome in medaka (Japanese killifish, Oryzias latipes) embryos. Specifically, we developed a method to ectopically induce the repressive histone modification, H3K27me3 in a locus-specific manner, using a fusion construct of Oryzias latipes H3K27 methyltransferase Ezh2 (olEzh2) and dCas9 (dCas9-olEzh2). Co-injection of dCas9-olEzh2 mRNA with single guide RNAs (sgRNAs) into one-cell-stage embryos induced specific H3K27me3 accumulation at the targeted loci and induced downregulation of gene expression. In this study, we established the in vivo epigenome editing of H3K27me3 using medaka embryos. The locus-specific manipulation of the epigenome in living organisms will lead to a previously inaccessible understanding of the role of epigenetic modifications in development and disease.