胚胎状态

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cytoplasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methylation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribution of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cyto-plasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methy-lation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribu-tion of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastcysts fellowed by fusion of cytoplasm and nucleus and cleavage in vitro.After fusion of cytoplasm, the DNA methylation levels of the fused embryos was very high as well as two-cell diploid embryos in vivo.Then the embryos was rapiddly demethylated when the nucleus begin to fuse, resulting the lowest DNA methylation levels when the nucleus fused completely.After that, the DNA methylation levels of fused embryos were gradually increased until the blastocysts stage.However, whereas an asymmetric distribution of DNA methylation was established in an vivo-derived blastocysts with a higher methylation level in the inner cell mass than in the trophectoderm, in most vitro-derived tetraploid blastocysts, we can not detect the asymmetric distribution.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在囊胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

But in 2007, scientists made a revolutionary breakthrough. Three different groups simultaneously announced that they had converted unipotent, mature skin cells back into an undifferentiated state. In other words, they had created cells that behaved like embryonic stem cells without using any embryo derived materials.

可是在2007年时，科学家们取得了革命性的突破，三个不同的小组同时宣布他们能够把已分化、成熟的表皮细胞转会一种未分化的状态，换句话说，他们制造了一种类似胚胎干细胞的细胞，但没用到任何源于胚胎的原料。

In conclusion, either electrofusion parameter or developmental stage of donor embryos have a significant effect on the efficiency of NT, NT embryos require different concentration of serum at their different development stages.

结果表明，电融合参数和供体胚胎的发育阶段以及受体卵母细胞的状态对NT效果有显著影响，在NT胚胎的不同发育阶段采用不同的血清种类和浓度可提高其胚胎发育能力。

Objective: To optimize the culture system of hEGcs in vitro, select the hEGcs from subculture to transplant directly to the rat infarcted myocardium and observe the therapeutic mechanism of their heterotransplantation in the treatment for the rat myocardial infarction.

目的：优化人胚胎生殖细胞的体外培养体系，并将生长状态良好的传代的人EG细胞移植用于大鼠心肌梗死模型的治疗，探讨人胚胎生殖细胞进行异种移植对大鼠心肌梗死的治疗机制。

During the process of nuclear reprogramming, the zygotes of the normal embryos and the donor nuclei of thecloned embryos cease their unique repertoire of gene expression and reset their gene expression to the totipo-tent status, and then the normal and cloned embryos redifferentiate from the totipotent status to variousdifferentiated states for tissue generation or organogenesis.

通过细胞核重编程，首先，受精卵和克隆胚胎的供体核停止其特有的基因表达程序，恢复为全能状态的基因表达程序；然后，受精胚胎和克隆胚胎的细胞再从全能状态重新进入分化状态，最终形成各种组织和器官。

In this study, we used mRNA Differential Display to analysis the change of gene expression pattern of mouse embryo in the above two stages and the effect of releasing the transcriptionally repressive state on the embryonic development.

为了研究胚胎发育早期基因表达模式的变化及其生理意义，我们使用mRNA差异显示的方法分析了小鼠胚胎基因组激活初期（1-2细胞胚胎）表达的mRNA及随后在二细胞胚胎中转录呈抑制状态的基因表达产物，并探讨了解除二细胞胚胎中转录抑制状态对胚胎后继发育的影响。

Thus, even in civilized communities, the embryo man passes through the hunter stage of development.

可见，甚至在文明社会中，处于胚胎状态的人，要经过一个渔猎者的发展阶段。

Nevertheless, whatever may be the contrast, all these toilers, from the highest to the most nocturnal, from the wisest to the most foolish, possess one likeness, and this is it: disinterestedness.

巴贝夫（Babeuf，1760？797），法国革命家，空想平均共产主义的著名代表，平等派密谋的组织者。一个处于胚胎状态的鬼域里的世界，这是多么离奇的形相！

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失