Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Sao Paulo, SP, Brazil.
Department of Animal Science, Michigan State University, East Lansing, MI, USA.
Methods Mol Biol. 2023;2647:59-81. doi: 10.1007/978-1-0716-3064-8_3.
Early cell specification in mammalian preimplantation embryos is an intricate cellular process that leads to coordinated spatial and temporal expression of specific genes. Proper segregation into the first two cell lineages, the inner cell mass (ICM) and the trophectoderm (TE), is imperative for developing the embryo proper and the placenta, respectively. Somatic cell nuclear transfer (SCNT) allows the formation of a blastocyst containing both ICM and TE from a differentiated cell nucleus, which means that this differentiated genome must be reprogrammed to a totipotent state. Although blastocysts can be generated efficiently through SCNT, the full-term development of SCNT embryos is impaired mostly due to placental defects. In this review, we examine the early cell fate decisions in fertilized embryos and compare them to observations in SCNT-derived embryos, in order to understand if these processes are affected by SCNT and could be responsible for the low success of reproductive cloning.
哺乳动物着床前胚胎的早期细胞特化是一个复杂的细胞过程，导致特定基因的协调空间和时间表达。正确分离为两个主要细胞谱系，内细胞团（ICM）和滋养外胚层（TE），对于胚胎和胎盘的正常发育是至关重要的。体细胞核移植（SCNT）允许从分化细胞核中形成含有 ICM 和 TE 的囊胚，这意味着这个分化的基因组必须被重新编程为全能状态。尽管通过 SCNT 可以有效地生成囊胚，但 SCNT 胚胎的完全发育受到损害，主要是由于胎盘缺陷。在这篇综述中，我们检查了受精胚胎中的早期细胞命运决定，并将其与 SCNT 衍生胚胎中的观察结果进行比较，以了解这些过程是否受到 SCNT 的影响，并可能是生殖克隆成功率低的原因。
