中胚层细胞的

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。

Most researchers reported that neuroendocrine cell's were the results of stem cell's multi-directional differentiation, like epithelial cell, which is originated from endoderm multipotential stem cells.

多数研究认为，神经内分泌（neuroendocrine，NE）细胞和上皮细胞均来自内胚层多潜能干细胞，是肿瘤发生过程中干细胞多向分化的结果。

Germ potential is established after conception in a totipotent zygote and retained subsequently during development in blastomers of morula , cells form the inner cell mass of blastocyst , epiblast and population of primordial germ cells .

种子潜能的确定是全能的受精卵形成之后，并且随后在桑葚胚，胚泡内层细胞，外胚层和原生殖细胞的发育过程中保留。

AFGF shows greatpotential for clinical applications for therapy of a variety of diseases, such as Parkinson'sdisease, spinal cord contusion injury, neural regeneration in reimplantation of broken-offfinger, brain ischemia, renal ischemia, myocardial infarction, occlusive vascularitis, retinalischemia, gastric ulcer and nonhealing wound and so on. We expressed human acid fibroblast growth factor gene transiently in tobacco byAgro-bacterium mediated vacuum infiltration and studied the factors, which influenced theexpression level.

人类酸性成纤维细胞生长因子(aFGF，FGF-1)是成纤维细胞生长因子超家族成员，来自于三个胚层的多种细胞都可以表达aFGF.aFGF在治疗帕金森综合症、急性脊柱扭曲性损伤、断指中神经功能重建、脑缺血、肾缺血、心肌梗塞、闭塞性脉管炎、视网膜缺血、胃溃疡及难愈合性伤口等多种临床应用方面具有巨大潜力。

This process, called vasculogenesis ,involves the de novo differentiation of endothelial cell from mesodermal precursor to form the primitive blood vessel network.

血管生成是指在胚胎发生和器官形成过程中，从中胚层内皮细胞中分化出新的内皮细胞以形成原始血管网的过程，仅见于胚胎发生的早期，出生后即停止。

In a giving stage after pollination,p53 homologue showed high levels in the antipodal cells,integument,immature endosperm,ovary wall,tracheary elements,and aleurone layer,while c-myc homologue showed low levels in these tissues,only before pollination showed high expression in polar nucleus.

结果发现，在授粉后的一定阶段，在反足细胞、珠被、未成熟的胚乳、子房壁、导管组织和糊粉层中，p53同源基因表达强烈，c-myc同源基因的表达相反，在授粉后的这些组织中基本不表达，而在授粉前的中央细胞的极核中表达水平较高。

The galactosyl oligosaccharides of raffinose series are widely distributed in seeds of many species and are localized in tissues that remain viable after desiccation, including the embryo and aleurone layer of cereals, cotyledons and axis tissues of legumes and other dicots.

棉子糖半乳糖苷系列寡糖广泛分布在许多种植物种子中，并存在于干燥后仍能保持活力的组织内，如禾谷类种子的胚及糊粉层，豆类及其他双子叶植物的子叶和胚轴组织等。棉子糖半乳糖苷系列寡糖在禾谷类种子的非自溶性中央胚乳中不合成，但存在于蓖麻种子的自溶性胚乳细胞中。

In this study, in utero transfection plasmid DNA method was set up to embryonic mouse. The GFP expression vector pCAGGS-IRES-EGFP was microinjected into the lateral cerebral ventricle of E 14.5d mouse embryos through the uterine wall. Then, the 30 V square-wave pulse was delivered across the head for 5 times and interval 50m sec by electrodes in parallel with the median raphes.

本研究旨在通过子宫内电穿孔法，建立鼠胚大脑皮层体内基因转移体系：将带有绿色荧光蛋白的表达载体pCAGGS-IRES-EGFP显微注入胚胎期14.5 d的鼠胚侧脑室中，电极沿与脑中缝平行的方向夹持鼠脑，在电压30 V，脉冲时间50 ms，脉冲数5的条件下方波电击，将外源基因转移到室管膜层细胞。

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