胚细胞

Toreniafournieri. has a naked embryo sac that protrudes from the micropyle into the cavity between the funiculus and placenta. As embryo sac is mature, the egg cell, the two synergids and about half the central cell are located outside the micropyle.

蓝猪耳在其发育的四核期，胚囊从珠孔端伸出，当胚囊完全成熟时，助细胞、卵细胞和大部分中央细胞均暴露于胚珠组织之外，是研究被子植物受精和胚囊发育的模式植物。

Results coculture with endometrial epithelial cells could promote the formation of mouse morula (71.3% and 61.2%,p.05) and blastocyst (50.0% and 39.7%,p.05), and increase the blastocyst hatched rate (34.8% and 24.3%,p.05) and total cell number of blastocyst (44.1 and 35.6, p.05).conclusion coculture with endometrial epithelial cells can facilitate the development of early mouse embryo in vitro, which can optimize the condition of embryonic development in vitro.

结果：与无上皮细胞相比，共培养明显促进了小鼠桑椹胚率（71.3%和61.2%，p.05），囊胚率（50.0%和39.7%，p.05），囊胚孵化率（34.8%和24.3%，p.05）和胚胎总细胞数（44.1和35.6，p.05）。结论：子宫内膜上皮细胞能够促进小鼠胚胎的体外发育，对早期胚胎的体外发育环境具有优化作用。

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。

Self-pollination was brought as the essential reason for causing emptied seeds by former researchers. Based on those studies, potassium antimonate and electron microscopy were used to study the calcium distribution of pollens in the micropylar canal of self-pollinated and cross-pollinated ovules and morphological changes in certain cells undergoing programmed cell death from pollination to fertilization, and observation of histo-chemical changes during microgametopyte development was performed by paraffin section.

前人研究认为自交是华北落叶松产生空粒的主要原因，本论文在此基础，运用焦锑酸钾沉淀法配合电镜观察研究了传粉后到受精前异交控制和自交辅助授粉胚珠珠孔道内花粉的钙分布情况，及此过程中细胞程序化死亡超微结构的变化，并通过石蜡切片研究了华北落叶松传粉后到受精前雌配子体发育过程及细胞内含物的变化，以研究在受精前胚珠内是否存在花粉识别与选择系统，探讨钙信号传导和花粉与胚珠相互作用及细胞程序化死亡的关系。

The results indicated, somatic embryos of Lycium barbarum L. mostly came from single embryogenic cell. Finaly, embryogenic cell grew into plant after bicellular, tricellular and multicellular stage.

结果发现，枸杞的体细胞胚是单细胞起源，经胚性细胞，二、三、四和多细胞原胚，到球形胚，最后发育成完整植物。

When electric fusion method was used for nuclear transfer, the fusion rate (46. 0%), cleavage rate (53. 9%) and blastocyte development rate (10.9%) of adult ear fibroblasts were significantly lower than that of fetal fibroblasts (64. 5%, 70.1%, 21. 6% respectively), fetal skin cells (71. 5%, 70.8%, 22. 1% respectively) and ovary granulosa cells (88. 2%, 79. 1%, 25. 5% respectively). There was no significant difference among other donor cells in the cleavage and blastocyst development rate of resconstituted embryos.

当用电融合法进行核移植时，成体耳部成纤维细胞的融合率（46.0％），卵裂率（53.9％）和囊胚发育率（10.9％）均显著低于胎儿成纤维细胞（64.5％，70.1％和21.6％），胎儿皮肤细胞（71.5％，70.8％和22.1％），以及卵巢颗粒细胞（88.2％，79.1％和25.5％）；另外三种细胞间的卵裂率，囊胚发育率无显著差异，但卵巢颗粒细胞的融合率显著高于胎儿成纤维细胞和胎儿皮肤细胞（88.2％vs 64.4％，71.5％，P＜0.05）。

Megaspore development and abortion of"Pingyi Tiancha"Compar-ing with regular developing megaspore of normal M.baccata,the megasporemother cellof"Pingyi Tiancha"could form mono-nucleus embryo sacby perhaps irregular meiosis,then most of sexual MES depauperatedand degenerated,finally aborted,or only a few further developed.Of asexualembryo sac,one or more large cells at the chalazal end of nucellus developed in-to one to more asexual embryo sac initials.After the competition between sexu-al embryo sacand asexual embryosac,most ovules only had one asexual embryo sac matured.

平邑甜茶大孢子的发育和败育与正常发育的山定子大孢子对比，平邑甜茶大孢子母细胞经减数分裂能形成单核胚囊，之后多数有性胚囊萎缩、退化而败育，只有极少数进一步发育；而无性胚囊则从胚珠合点端1个或多个较大的珠心细脆形成并首先发育为一个或多个无性胚囊原始体；经过有性胚囊和无性胚囊以及无性胚囊和无性胚囊之间的竞争，多数胚珠只有一个无性胚囊成熟。

Morphology of sexual reproduction abortion in'High Noon', a distant hybridization cultivar of tree peonies(P.delavayi var. lutea×P. suffruticasa), was systematically investigated with light microscopy and cross. The results indicated that:(1)The stamens matured earlier than the gynoecia and pollens dispersed at the early stage of anthesis but the rate of normal 2-celled pollens were merely 2.41%.

采用光镜和杂交等方法对牡丹远缘杂交一代品种'正午'有性生殖败育进行系统形态学观察发现：(1)雄蕊较雌蕊先成熟，初花期即散粉，正常2-细胞花粉仅占2·41%，且花粉在多种培养液中、在自身和其它两种柱头上均不萌发；柱头在谢花期大量分泌粘液，进入最佳授粉状态；(2)同一胚珠中多个大孢子母细胞减数分裂高度不同步，胚囊发育与受精延迟，部分胚乳游离核在细胞化时期分裂异常；(3)自花及品种内异花授粉不结实，天然授粉结实率为0·053‰~0·130‰。

DC have been studied by using the cytochemical methods. The results showed that the cytoplasm of the haustorial cells, the degenerating sites of integumentary cells and nucellar cells surrounding haustorial cells showed strong PAS staining.

DC的胚乳吸器进行了细胞化学研究，结果显示，胚乳吸器的细胞质、胚乳吸器周围解体的珠心细胞和珠被细胞均呈强PAS正反应。

We generated EG4-GFP cell lines expressing enhancing green fluorescence protein which still maintained typical characteristics of pluripotent stem cells. We microinjected green cells into perivitelline of 8-cell stage embryos as well as aggregated them to 8-cell stage embryos with zona pellucida removed, to investigate developmental fate of EG4-GFP cells during formation of chimeric blastocysts.

我们建立了稳定表达绿色荧光蛋白的EG细胞系（EG4-GFP），发现该细胞仍能保持野生型的一般生长特性；通过显微注射和体外聚集得到细胞与8-细胞受体胚胎共同发育形成的嵌合胚，发现转基因细胞参与了胚胎早期发育过程中的生长与分化，大部分细胞集中于内细胞团，也有细胞分化为滋胚层细胞。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。