印迹基因修饰使孤雌胚胎干细胞获得四倍体补偿能力

Imprinting genes modified parthenogenetic embryonic stem cells produce full-term mouse via tetraploid complementation

摘要:

孤雌胚胎干细胞 (Parthenogenetic embryonic stem cells，pESCs) 的遗传物质全部来源于母源基因组，因缺失父源基因而不具备四倍体补偿的能力。为了使pESCs也具备发育到个体的能力，呈现与受精卵来源ESCs类似的多能性，文中借助CRISPR/Cas9系统对孤雌来源的pESCs中的2个重要母源印迹基因的差异甲基化区域 (Differentially methylated region，DMR) 进行单等位基因敲除 (H19-DMR，IG-DMR)，获得双基因敲除的 (DKO) pESCs。结果表明，pESCs虽然来源于母源基因组，但是其形态特征、多能干性标记分子的表达水平、体外神经分化能力与受精卵来源的ESCs基本一致。最后，通过基因修饰的DKO pESCs可以通过四倍体补偿获得发育到期的胎儿，表明经过印迹基因修饰的pESCs也具有发育到一个完整个体的多能性。从而为再生医学研究提供了一类具有主要组织相容性复合基因匹配且多能性良好的资源细胞。

Abstract:

Parthenogenetic embryonic stem cells (pESCs) derived from bi-maternal genomes do not have competency of tetraploid complementation, due to lacking of paternal imprinting genes. To make pESCs possess fully development potentials and similar pluripotency to zygote-derived ESCs, we knocked out one allelic gene of the two essential maternal imprinting genes (H19 and IG) in their differentially methylated regions (DMR) via CRISPR/Cas9 system and obtained double knock out (DKO) pESCs. Maternal pESCs had similar morphology, expression levels of pluripotent makers and in vitro neural differentiation potentials to zygotes-derived ESCs. Besides that, DKO pESCs could contribute to full-term fetuses through tetraploid complementation, proving that they held fully development potentials. Derivation of DKO pESCs provided a type of major histocompatibility complex (MHC) matched pluripotent stem cells, which would benefit research in regenerative medicine.