Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200135, China.
Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai 200135, China.
Proc Natl Acad Sci U S A. 2022 Mar 22;119(12):e2115248119. doi: 10.1073/pnas.2115248119. Epub 2022 Mar 7.
In mammals, a new life starts with the fusion of an oocyte and asperm cell. Parthenogenesis, a way of generating offspring solelyfrom female gametes, is limited because of problems arising fromgenomic imprinting. Here, we report live mammalian offspringderived from single unfertilized oocytes, which was achieved by tar-geted DNA methylation rewriting of seven imprinting control regions.Oocyte coinjection of catalytically inactive Cas9 (dCas9)-Dnmt3a ordCpf1-Tet1 messenger RNA (mRNA) with single-guide RNAs (sgRNAs)targeting specific regions induced de novo methylation or demethyla-tion, respectively, of the targeted region. Following parthenogeneticactivation, these edited regions showed maintenance of methylationas naturally established regions during early preimplantation develop-ment. The transfer of modified parthenogenetic embryos into fostermothers resulted in significantly extended development andfinally inthe generation of viable full-term offspring. These data demonstratethat parthenogenesis can be achieved by targeted epigenetic rewrit-ing of multiple critical imprinting control regions.
在哺乳动物中，新生命始于卵子和精子细胞的融合。孤雌生殖是一种仅从雌性配子产生后代的方式，但由于基因组印记引起的问题，其应用受到限制。在这里，我们报告了通过靶向 DNA 甲基化重写七个印迹控制区域，从单个未受精的卵母细胞中获得的活的哺乳动物后代。通过将具有 sgRNA 的无活性 Cas9 (dCas9)-Dnmt3a 或 Cpf1-Tet1 mRNA 与靶向特定区域的 sgRNA 共注射到卵母细胞中，分别诱导靶向区域的从头甲基化或去甲基化。进行孤雌生殖激活后，这些编辑区域在早期胚胎植入发育过程中表现出与自然建立的区域一致的甲基化维持。将经过修饰的孤雌生殖胚胎移植到代孕母亲体内，可显著延长发育时间，最终成功产生具有活力的足月后代。这些数据表明，通过靶向多个关键印迹控制区域的表观遗传重写可以实现孤雌生殖。
