胚胎

There is increasing evidence that development of preimplantation embryo is regulated by maternally and embryonically derived growth factors.

大量研究证据表明，许多生长因子和受体存在于早期胚胎和雌性生殖道中，哺乳动物早期胚胎的发育受到母源和胚胎自身生长因子的调节，生长因子以旁分泌、自分泌和内在分泌的方式作用于胚胎，调节胚胎细胞的功能。

Among the 20 samples of IGF- 1 group, a 8-cell stage embryo, a morula and two blastula were found as positive by the red colour appearance .

IGF上的表达 2～8细胞胚胎 18个，桑堪胚 1个，囊胚 2个，共计 ZI个胚胎用于＊F2 检测，阳性表达14个，其中强阳性表达7个，弱阳性表达7个，分布于各阶段胚胎，在胚胎细胞中呈现深、浅程度不同的橘红色染色。l级和 2级胚胎 IGFZmRNA的阳性表达差异有显著性。

These observations show that reprogramming is easier in interspecific embryos reconstructed with ES cells than that reconstructed with somatic cells, and that ES cells have the higher ability to direct the reconstructed embryo development normally than fibroblast cells. Oocytes were reconstructed with outbreeding Kunming albino mouse ES cells and enucleated rabbit oocytes, and the effects of the passages of ES cells and 6-DMAP on the development of interspecific reconstructed oocytes were analyzed. The interspecific reconstructed ES-rabbit oocytes were activated either by combined two set electric pulses and 6-DMAP or by two set electr

以上结果显示，6－DMAP能增加胚胎干细胞异种重构卵的卵裂率，对重构卵囊胚的发育率影响不大；高培养代数和低培养代数的胚胎干细胞用于异种核移植不影响异种重构卵的卵裂率和囊胚发育率；用胚胎干细胞作为供核细胞；比体细胞作为供核细胞所构建的异种重构胚更容易进行重编程，并且胚胎于细胞指导异种克隆胚胎正常发育的能力强于体细胞。

The toxicity of cryoprotectans increased as the concentration of its increased.3, the survival rate of embryos microinjected with 6M PM was 25.07±1.57% after being coolled in -20℃ for 10 minutes by programmed cooling method, whenas ,the survival rate of controls dealt with five steps balance method was 20.88±2.84%, which indicated that the chilling sensitivity of embryos with microinjection decreased.

而任何一种抗冻剂均随着浓度的增加其毒性随之增加。3、另外，在冷敏感实验中，显微注射6M的PM的胚胎胚胎，应用程序化法处理，以2℃/min的速率降至-20℃，平衡10min后解冻处理，发现注射PM的胚胎低温处理后成活率为25.07±1.57%，而6M的PM五步平衡法同步处理的对照组胚胎成活率为20.88±2.84%，说明显微注射的胚胎冷敏感性一定降低。

According to the mechanism of block of development in vitro culture on early embryo of mammal and in vivo surroundings of early embryo, the paper states that requirement and utilization of nutrients during each cell stage of early embryo of mammal in vitro culture in order to search for in vitro culture condition and method to improve the development rate of blastosphere.

摘要从哺乳动物早期胚胎体外培养发育阻断机理和早期胚胎的体内环境入手，阐述了胚胎体外培养各细胞阶段胚胎对营养物质的需求，寻求合理的体外培养条件和方法，以便提高体外胚胎早期的囊胚发育率。

Results: NKA-I cells was first found in the duodenum mucose on the 14th day of fetus, earlier than in the jejunum ( 16th day ) and ileum ( 17th day ), and its Positive reaction and the number of cells increased with further development, after birth the 30th day, it became quite identical to that of adult rat; NKA-I cells were seen in the colon mucosa on the 17th day of fetus, later on the number kept decreasing till grown up stage; No change was observed in the stomach mucosa except that few cells showed up on the 15th day of fetus; No positive cell was found on the oesphagus wall.

结果： NKA-I细胞首先见于胚胎14 d的十二指肠粘膜，早于空肠(胚胎16 d)和回肠(胚胎17 d)，其阳性反应强度及细胞量随发育而增加，30 d时与成年鼠相似；结肠粘膜内于胚胎17 d见细胞，但此后数量较少直至成年；胃粘膜于胚胎15 d见个别细胞外，以后无明显变化；食道壁始终未见阳性细胞。

Results: NKA-I cells was first found in the duodenum mucose on the 14th day of fetus, earlier than in the jejunum ( 16th day ) and ileum ( 17th day ), and its Positive reaction and the number of cells increased with further development, after birth the 30th day, it became quite identical to that of adult rat; NKA-I cells were seen in the colon mucosa on the 17th day of fetus, later on the number kept decreasing till grown up stage; No change was observed in the stomach mucosa except that few cells showed up on the 15th day of fetus; No positive cell was found on the oesphagus wall.

结果：NKA-I细胞首先见于胚胎14 d的十二指肠粘膜，早于空肠(胚胎16 d)和回肠(胚胎17 d)，其阳性反应强度及细胞数量随发育而增加，30 d时与成年鼠相似；结肠粘膜内于胚胎17 d见多个细胞，但此后数量较少直至成年；胃粘膜于胚胎15 d见个别细胞外，以后无明显变化；食道壁始终未见阳性细胞。

He experiment proved that pre-implantation embryos are more sensitive than post-implantation ones, suggested TCDD may exert its effect before implantation, or at this process. 3. The toxicity of TCDD on the early embryo can be of omnifarious. It can strongly inhibit DCR, which represent mother toxicity; It cause un-synchronizated cleavage of pre-implanted zygote and pre-implanted embryo loss; It also decreases implantation sites in the uterus, and continued to effecting the uterus of pregnant mouse, cause the decreased number of fetus before birth. 4. TCDD exposure changed reproductive hormone level of pregnant mouse.

CDD对胚胎的毒性影响可能是多方面的：强烈抑制子宫蜕膜细胞反应，表现出典型的母体毒性；虽然没有影响胚胎转运速度，但造成着床前胚胎的丢失和发育不同步；早期染毒降低了第9天的胚胎着床数，同时使出生前第18天胚胎成活数继续减少。

Analysis of mitochondrial DNA composition of the panda-rabit cloned embryos found that mitochondria from both panda somatic cells and rabbit ooplasm co-existed in early blastocyst, but mitochondria from rabbit ooplasm decreased and those from panda donor cells dominated in early fetuses after implantation.

结果显示，应用卵裂球电融合方法可以制作一系列的多倍体胚胎；小鼠囊胚的形成与胚胎中的细胞数目无直接关系，卵裂球的电融合和染色体数目的增加不会改变胚胎的发育进程；而胚胎细胞中的核／质比可能是控制胚胎囊胚化的一个重要因素。

BACKGROUND: At present, studies show that a kind of stem cell community which in many kinds of organizations can differentiate into tissue cells of different embryonic layers; but those are different from embryonic stem cells, embryonic stem cell will lose the part differentiation potential gradually during the development of pregnancy, and will present some special phenotypes or the molecular markers, as CD105 and so on, will call it postembryonic pluripotent stem cells.

背景：目前研究认为在胚胎发育后的多种组织中存在一类干细胞群体，可分化为不同胚层的组织细胞；但又不同于胚胎干细胞，随着妊娠期间胚胎的发育胚胎干细胞会逐渐失去部分分化潜能，会出现一些特殊表型或分子标记，如CD105，称其为胚胎后亚全能干细胞。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。