胚胎

Based on the fossil embryos from the Weng'an biota, present study aims at answering questions about the origin of animals in aspect of embryological and developmental biology.

本文主要从演化发育生物学和胚胎生物学的角度，以瓮安生物群中的胚胎化石为研究对象，探索动物起源和进化中的一些科学问题。

One hundred twenty three years after Haeckel's publication, Michael Richardson, an embryologist at St.

直到一九九七年，在伦敦圣乔治医院医科大学的胚胎生物学家理查森重新观察和拍摄了鱼，蝾螈，鸡和人早期胚胎的形象。

Embryology The study of the development of embryos, usually from fertilization.

胚胎学：是研究胚胎发育的学科，通常从受精开始。

In zebrafish, the expression of fez becomes detectable at the anterior edge of the presumptive neuroectoderm by 70% epiboly.

本文用整体原位杂交的方法揭示了在斑马鱼胚胎发育过程中，Fez基因的表达最早出现在原肠期胚胎头部未来的神经外胚层细胞中，此时胚盘仅下包约70％。

Epiboly Movement of the embryonic cell mass over the surface of the yolk?; the germ ring marks the boundary of the advancing sheet of cells.

外包胚胎细胞团移动通过卵黄的表面上；胚胎环细胞正好标志出细胞前进的边界。

Temporal and spatial expression pattern of gibel carp pou2 during embryogenesis was investigated by RT-PCR and whole-mount in situ hybridization. RT-PCR result indicates that there is maternal transcript of gibel carp pou2 in early embryos and the zygotic pou2 transcript is abundantly expressed from blastula stage. Large amount of pou2 transcript is detected at both 50% and 90% epiboly stages. At 100% epiboly stage, however, the pou2 transcript reduces rapidly and disappears at the later embryogenesis. Whole-mount in situ hybridization shows that the maternal transcript ubiquitously exists in all blastomere cells.

我们用RT-PCR和整体原位杂交的方法研究了银鲫pou2基因在胚胎发育过程中的时空表达图式RT-PCR结果显示，银鲫pou2基因有母源转录本，其合子基因在高囊胚期强烈表达，在50%下包期和90%下包期也有高量的转录本，但在100%下包期表达量急剧降低，至体节期时已经完全检测不到其转录本胚胎整体原位杂交结果显示其母源转录本在所有的胚盘细胞中。

"Evolution" was first used in Preformationism and then in Epigenesis, respectively, to describe the unfolding of preexisted organic structure and the recapitulation of the forms of lower animals by the embryo of higher animals. Then the meaning of species change was added to it in the beginning of the nineteenth century.

"Evolution"一词先后被用在胚胎学的预成论和后成论中，分别用来描述预先存在的有机体结构的展开以及高等动物胚胎对低等动物形式的重演。19世纪初它又被添加上了物种改变的含义。

"Evolution" was first used in Preformationism and then in Epigenesis, respectively, to describe the unfolding of preexisted organic structure and the recapitulation of the forms of lower animals by the embryo of higher animals. The n the meaning of species change was added to it in the beginning of the nineteenth century.

"Evolution"一词先后被用在胚胎学的预成论和后成论中，分别用来描述预先存在的有机体结构的展开以及高等动物胚胎对低等动物形式的重演。19世纪初它又被添加上了物种改变的含义。

During the two critical periods—gametogenesis and preimplantation development, there are genome-wide epigenetic reprogramming in gametes and embryos, which plays important roles in the erasion or creation of imprinting, gene silencing and tissue-specific gene expression.

其中关键时期是配子形成期和胚胎植入前期，最主要内容是全基因组DNA"CpG岛"甲基化和染色质组蛋白乙酰化的有规律变化，结果是配子遗传印记的消除与重建、植入前胚胎大范围基因的静默和组织特异性基因表达的确定。

Expression was predominantly in extraembryonic tissues of E7.5 mouse embryo.

ZNF18主要在E7.5小鼠胚胎的胚外组织表达，E8.5出现了胚胎躯干前端表达。

It seems likely that Kraft will return with a better offer.

看起来卡夫要重新考虑一个更好的出价了。

But he'd rather burn off my feelers and watch me squirm.

可他却放任那个家伙对我为所欲为！