Somatic cell-like features of cloned mouse embryos prepared with cultured myoblast nuclei
Somatic cell-like features of cloned mouse embryos prepared with cultured myoblast nuclei
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DOI：
10.1095/biolreprod.102.014522
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发表时间：
2003-07-01
影响因子：
3.6
通讯作者：
Latham, KE
中科院分区：
文献类型：
--
作者：
Gao, SR;Chung, YG;Latham, KE
通过体细胞核移植进行克隆需要沉默供体细胞基因表达程序并启动胚胎基因表达程序（核重编程）。未能沉默供体细胞程序可能会导致胚胎表型改变。使用成肌细胞核产生的克隆小鼠胚胎在标准胚胎培养基中无法生长，但在供体成肌细胞喜欢的体细胞培养基中生长良好；在大多数胚胎中，以显着的速率形成囊胚，具有稳健的形态、高的细胞总数以及细胞向内细胞团的正常分配。成肌细胞克隆胚胎继续表达 GLUT4 葡萄糖转运蛋白，该转运蛋白通常在肌肉中表达，但在植入前阶段胚胎中不表达。成肌细胞克隆还表现出细胞表面 GLUT1 的早熟富集。成肌细胞和卵丘细胞克隆胚胎均表现出较高的葡萄糖摄取率。这些观察结果表明，克隆过程中供体细胞基因组的沉默要么是不完全的，要么是在植入前发育过程中逐渐发生的。因此，克隆胚胎最初表现出许多体细胞样特征。四倍体构建体具有移植的体细胞基因组和卵母细胞衍生的染色体，表现出更类似于胚胎的基因表达模式和培养偏好。我们的结论是，植入前阶段的克隆胚胎已深刻改变了供体细胞类型特异性的特征，并且将克隆胚胎暴露于标准胚胎培养条件可能会导致基本稳态的破坏和一系列重要过程的抑制，包括进一步的核重编程，从而导致克隆胚胎死亡。
Cloning by somatic cell nuclear transfer requires silencing of the donor cell gene expression program and the initiation of the embryonic gene expression program (nuclear reprogramming). Failure to silence the donor cell program could lead to altered embryonic phenotypes. Cloned mouse embryos produced using myoblast nuclei fail to thrive in standard embryo culture media but flourish in somatic cell culture media favored by the donor myoblasts; themselves, forming blastocysts at a significant rate, with robust morphologies, high total cell number, and a normal allocation of cells to the inner cell mass in most embryos. Myoblast cloned embryos continue expressing the GLUT4 glucose transporter, which is typically expressed in muscle but not in preimplantation stage embryos. Myoblast clones also exhibit precocious enrichment of GLUT1 at the cell surface. Both myoblast and cumulus cell cloned embryos exhibit enhanced rates of glucose uptake. These observations indicate that silencing of the donor cell genome during cloning either is incomplete or occurs progressively over the course of preimplantation development. As a result, cloned embryos initially exhibit many somatic cell-like characteristics. Tetraploid constructs, which possess a transplanted somatic cell genome plus the oocyte-derived chromosomes, exhibit a more embryonic-like pattern of gene expression and culture preference. We conclude that preimplantation stage cloned embryos have profoundly altered characteristics that are donor cell type specific and that exposure of cloned embryos to standard embryo culture conditions may lead to disruptions in basic homeostasis and inhibition of a range of essential processes including further nuclear reprogramming, contributing to cloned embryo demise.