Oct4 distribution and level in mouse clones:: consequences for pluripotency
Oct4 distribution and level in mouse clones:: consequences for pluripotency
复制标题
DOI：
10.1101/gad.966002
复制
发表时间：
2002-05-15
影响因子：
10.5
通讯作者：
McLaughlin, KJ
中科院分区：
文献类型：
--
作者：
Boiani, M;Eckardt, S;McLaughlin, KJ
体细胞克隆通常在发育阶段与分化的开始时失败。转录因子OCT4在裂解阶段表达，对于胚泡的分化至关重要。 OCT4表达仅限于内部细胞质量和层细胞。胃分解后，Oct4仅在生殖细胞中活跃，并且在体细胞中保持沉默。在这里，将OCT4和OCT4-GFP转基因用作基因重编程可能与体细胞克隆的发育潜力直接相关的标记。库卢斯细胞克隆在正确的阶段启动了OCT4表达，但在大多数胚泡中显示出不正确的空间表达。克隆形成产物的能力降低了，而产物的产物具有较低甚至无法检测到的OCT4 RNA或GFP的水平。胚泡中GFP信号的质量与生成维持GFP表达的产物和胚胎茎（ES）细胞衍生的频率的能力相关。克隆中的OCT4异常表达是由重编程错误直接或间接引起的，这表明总体上未能重置遗传程序。异常的OCT4表达可能与其他关键发育基因的异常表达有关，导致各个胚胎阶段异常。无论其他基因如何，仅在OCT4水平上观察到的变化是目前在体细胞克隆中观察到的大多数故障。
Somatic cell clones often fail at a developmental stage coincident with commencement of differentiation. The transcription factor Oct4 is expressed during cleavage stages and is essential for the differentiation of the blastocyst. Oct4 expression becomes restricted to the inner cell mass and epiblast. After gastrulation Oct4 is active only in germ cells and is silent in somatic cells. Here, Oct4 and an Oct4-GFP transgene were used as markers for which gene reprogramming could be directly related to the developmental potential of somatic cell clones. Cumulus cell clones initiated Oct4 expression at the correct stage but showed an incorrect spatial expression in the majority of blastocysts. The ability of clones to form outgrowths was reduced, and the outgrowths had low or even undetectable levels of Oct4 RNA or GFP. The quality of GFP signals in blastocysts correlated with the ability to generate outgrowths that maintain GFP expression and the frequency of embryonic stem (ES) cell derivation. Abnormal Oct4 expression in clones is either directly or indirectly caused by reprogramming errors and is indicative of a general failure to reset the genetic program. The abnormal Oct4 expression may be associated with aberrant expression of other crucial developmental genes, leading to abnormalities at various embryonic stages. Regardless of other genes, the variations observed in Oct4 levels alone account for the majority of failures currently observed for somatic cell cloning.