胚细胞

Under appropriate conditions embryonic stem cells have been shown to differentiate in vitro to multiple cell types of endoderm, mesoderm and ectoderm.

一旦撤除分化抑制因素，或添加适当的诱导剂，ES细胞可分化为内胚层、中胚层和外胚层的多种类型的特化细胞。

In the gymnosperms the megaspore gives rise to a cell that is termed the embryo sac because of its similarity to the angiosperm structure.

在裸子植物中，大孢子也产生一个细胞，因为它类似于被子植物的胚囊细胞，故也可以称之为胚囊。

Nucellar cells degenerated in advance under low temperature, which resulted in thickened embryo sac wall surrounding the megasporocyte.

低温处理的蝴蝶兰，胚囊发育过程中珠心细胞提前退化，在大孢子母细胞外围形成较厚的胚囊壁。

Embryological observations on Crawfurdia delavayi, Tripterospermum cordatum, T. chinense, Gentiana striata and Pterygocalyx yolubilis show that the group under study is greatly diverse in differentiation and development of anther wall, type of ovule and placentae, synergid and antipodal cell in embryo sac, testa and embryogeny etc. The embryological characters are different among Crawfurdia, Tripterospermum and Gentiana Sect.

胚胎学 本文对披针叶蔓龙胆C.delavayi、双蝴蝶T.chinense、峨眉双蝴蝶T.cordatum、条纹龙胆G.striata和翼萼蔓P.voiubilis作了较详细的胚胎学研究，这些类群在花药壁的分化和形成、胚珠和胎座类型、卵器中的助细胞和反足细胞、种皮以及胚发育等特征上存在差异，并且在胚胎学特征上各自拥有原始和进化的性状。

In addition, certain endoderm marker genes expressed in the early stage during in vitro pancreatic differentiation means that these cells are endoderm-like cells.

此外，有内胚层的标的基因表现在体外胰脏诱导分化过程的早期阶段，显示这些细胞为与内胚层相似的细胞。

The endoderm cells in the induction group were numerous with polygon shape, while in the control group were small amount of long fusiform.

加入全反式维甲酸的诱导组内胚层细胞呈多边形且数量较多，对照组内胚层细胞呈长梭形且数量少。

The scientists noted that specialized cells generated from the AFS cells included all three classes of cells found in the deeloping embryo - termed ectoderm, mesoderm, and endoderm.

科学家还发现从羊水衍生的干细胞中生长出来的特定的细胞包含了发育的胚胎的三种细胞类型——外胚层、中胚层和内胚层。

The results indicated that the treatment of irradiation restrained the growth and differentiation of protocorm, especially to roots.The LD50 is 67.23Gy, because the protocorm is a integrate embryoids and higher tolerance was found. Ploidy analysis showed that most of aberrant seedlings go with the change of DNA and they were not euploid. When the plants trearted by irradiation, some of aberrant seedlings appeared stem forfication, and leaves appeared chlorophyll-deficient or green-white.,probably due to some genes' expression or closing.

结果表明：辐照处理对种胚原球茎的生长和分化有抑制作用，尤其是对根的抑制更为明显；由于种胚原球茎的完整性好，耐受性强，其辐照半致死剂量(LD50)为67.23Gy；流式细胞分析表明，大多数外部形态发生改变的植株其细胞内DNA的倍性发生了改变，出现相当多的非整倍体；此外，辐照产生的变异苗出现茎分叉、叶片缺绿或白绿相间等现象，可能是由于某些基因的表达与关闭引起的。

In the late of April of the second year, male inflorescences unbound and pollinated. When female inflorescences accepted the pollen grains, ovary development was increased in early May. With the development of either of the two ovule, funiculus, integument and nucellus were differentiated. Embryo sac mother cell came into being and the meiosis begins. Then fuctional megaspore developed into matured embryo sac that contain eight nucleuses. In the end of May, double fertilization generated.

次年，4月下旬，雄花序解螺旋散粉，雌花序开花授粉；5月上旬，雌花序授粉后，迅速增长，子房膨大，两个胚珠分化出珠柄、珠被和珠心，珠心中产生孢原细胞；5月中下旬，大孢子母细胞形成并减数分裂，功能性大孢子形成成熟的八核胚囊；5月底，发生双受精。

Deserticola showed polarity, with the micropyle cells being smaller than the chalazal ends and differentiated into white radicle-like organs.

肉苁蓉种胚具有明显的极性，珠孔端细胞小于合点端，珠孔端细胞分化、生长并产生白色的类胚根状结构。

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