胚胎

Results shows that the earlier the treatment starts, the more the decrease of gsc expression in late blastula, the fewer the number of somites at 24 h, and the more severe the defects in axial mesoderm. This suggests that maternal TGF-βsignals are activated immediately after fertilization and such activation continues before the onset of zygotic gene expression.

为了确定斑马鱼中母源TGFβ信号的激活时间，本研究用50μM SB-431542在中囊胚过渡期前(即合子基因开始表达之前)的不同时期处理胚胎，随后观察胚胎形态和检测分子标记的变化。

With the development of embryo, Myf5 expression decreased gradually in somites in the anterior region, but remained strong in the newly formed somites; After 30 somites formed, MyoD expression decreased in the somites except the caudal somites. At the hatching stage, MyoD and Myf5 were expressed in head muscle cells and fin muscle cells. In the growing fish, Myf5 was expressed in the skeletal muscle and intestine, and in adult flounder, Myf5 was only expressed in muscle. In the growing fish and adult fish, MyoD was only expressed in muscle.

在胚胎发育早期，Myf5在近轴中胚层中表达，体节发生过程中，Myf5在体节中表达，MyoD基因最早在分节板的体节前细胞中表达，随后在近轴细胞、体节中表达；随着胚胎的发育，Myf5在成熟体节中表达量降低，在新生体节中表达较强；MyoD自30个体节时期后只在新生的尾部体节中表达，在成熟的体节中表达量降低；在孵化期，MyoD和Myf5在头部及鳍的肌肉、尾部的体节中表达；生长期的牙鲆中，Myf5在骨骼肌和肠中表达，成体牙鲆中，Myf5只在肌肉中表达；生长期的牙鲆及成体牙鲆中，MyoD只在肌肉组织中表达。

They expressed prominently in the forebrain, mid-hindbrain boundary, branchial arches, somites, limb bud and tailbud of mouse embryos. These expression profiles indicate that Fgf8, Spry2 and Sef belong to a synexpression group and suggest that these genes may functionally interact during embryonic development.

在小鼠8.75天胚胎上（E8.75），这些基因在前脑，中脑和后脑的交界处，鳃弓，体节及尾芽等处有明显的表达，这些表达的相似性提示了它们可能在胚胎早期发育过程中的相互作用。

At 24 h, Ang1 was expressed mainly in the lens, optic cup, mesencephalon, ventral part of hindbrain, and myotomes in the somites, while zfTie2 was mainly expressed in intersomitic vessels including dorsal aorta and axial veins, and sprouting vessels from the dorsal aorta in the trunk. VEGF was expressed mainly in the lens, optic cup, mesencephalon and myotomes in the somites, while zfFlk1 was mainly expressed in intersomitic vessels including dorsal aorta and axial veins, and sprouting vessels from the dorsal aorta in the trunk.

结果从受精卵胚胎发育第12小时可见血管内皮细胞生长因子和血管发生素1及其相应受体flk1和Tie2的表达；在受精卵胚胎发育的第16小时，血管内皮细胞生长因子和血管发生素1主要在头部和尾部胚芽表达；第24小时在眼球、视窝、中脑、后脑的腹前侧和肌节中表达，Tie2和Flk1主要在肌间背部动脉血管、躯干新生血管芽和轴向静脉中表达。

In this process, the effect of many outside environmental factors can lead to abnormal embryo development, embryo death and fetal malformation.

在此过程中，外界环境中多种因素的影响都可能导致胚胎发育异常、胚胎死亡及胎儿畸形。

Early cleavage rate,embryo quality,the rate of blastocyst,implantation and pregnant rates from these zygotes were observed,and the transferred embryos were selected according to the pronuclei orientation and early cleavage time.

根据受精卵原核构型的不同分为四组，结合构型类型及早期卵裂与否进行选择性移植，通过观察优质胚胎率、囊胚形成率、种植率和怀孕率，来评估合子原核构型和早期卵裂与胚胎发育潜力的关系。

The relationship between embryonic development and changes of endogenous hormones in litchi ovules was studied.

以兰竹荔枝胚胎发育时期的正常胚珠与败育胚珠为试验材料，研究了胚胎发育与内源激素的关系。

The results show that eggs dissected from the lateral oviducts may cleave in the culture medium composed of TC - 100, plasma of larvae of its host Ostriniafurnacalis and fetal serum.

通过在体外条件下培养腰带长体茧蜂侧输卵管处解剖得到的脱去滤泡细胞的成熟卵及从寄生早期幼虫血淋巴中获得的初期胚胎，对腰带长体茧蜂卵和胚胎的初期发育进行了初步的研究。

The results show that: 1 supplementation of protein to maturation media improves cumulus expansion in vitro compared to the protein-free control, but cumulus expansion is not necessarily related to oocyte nuclear maturation in pigs, and cumulus expansion is not the criterae for determination of nuclear maturation of pig oocytes, but only the exclusion of the first polar body; 2 exposure of pig COCs to hormone supplements for 23-24 hours improved cumulus expansion but had no significant effect on nuclear maturation compared to that for 46-48 hours; 3 under our research conditions, supplementation of different proteins into different maturation media has different effects on porcine oocyte nuclear maturation, but has no significant effect on subsequent embryonic development after IVF; 4 the nuclear maturation rates of pig oocytes matured in mTCM+pFF and mNCSU+pFF are superior than that in mNCSU+FCS; 5 different maturation media have no effect on pig oocyte cumulus expansion and subsequent embryonic development after IVF.

结果显示：(1)在成熟液中添加蛋白质可以加强卵丘细胞的扩散，但猪卵母细胞的核成熟与其周围的卵丘细胞扩展没有必然的联系，卵丘细胞扩散或成放射状不宜作为猪卵母细胞核成熟的标准，只有排出第一极体才能作为猪卵母细胞核成熟的标志；(2)在猪COCs的46-48小时成熟培养的后23-24小时阶段去除成熟液中的激素不但可以保证卵母细胞的核成熟率，而且可加强卵丘细胞的扩散；(3)在现有实验条件下，在mTCM和mNCSU中添加10％pFF与在mNCSU中添加10％FCS相比可获得较高的猪卵母细胞核成熟率；(4)在不同的成熟液中添加不同的蛋白质对猪卵母细胞核成熟率的影响效果不一样，但对体外受精后的早期胚胎发育影响不明显；(5)成熟液种类对猪卵母细胞的卵丘细胞扩散和体外受精后的早期胚胎发育无显著影响。

The Geron team began its work with what is known as a Presidential stem cell line — stem cells derived from discarded in vitro fertilization embryos that already existed in 2001 when former President Bush decided to prohibit the use of federal funds to pursue human embryonic stem cell work.

Geron小组用一种被称为总统干细胞开始他们的工作---这种干细胞是从2001年起就存在的被遗弃的体外培养的胚胎中提取的，当时布什总统决定下令禁止使用联邦基金购买人类胚胎干细胞的研究工作。

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。