胚胎发育

The outside gill disappeared, the gill arches developed to from the branchia, later the branchia appeared primary protuberance, along with developing, it appeared the secondary protuberance and the third protuberance, until the 36 stage, the stage is the inside gill developing at the peak, later it came into the period of the metamorphosis, the inside gill degenerated, the third protuberance began shrank, next the secondary protuberance and the primary protuberance shrank, finally the gill arches shrank and disappeared, the metamorphosis completed.

内鳃的发育是首先由鳃弓上的突起形成鳃叶，其次鳃叶上出现初级突起，随着进一步发育出现次级突起和三级突起，直到内鳃发育最高峰(胚胎发育的36期)。随后进入变态期，内鳃开始退化，首先是三级突起开始萎缩，其次是次级突起和初级突起，最后是鳃弓，直至鳃弓完全消失，变态完成。

The snail was found to have an indirect developmental type in the early development. The fertilized eggs were oval-shaped and discoidal cleavage. Embryonic development stages were divided into cleavage, blastula, gastrulae, trochophore, and intra-membrane veliger. Larval development stages included veliger, late veliger and crawling larvae metamorphosed to juvenile.

结果表明：黄口荔枝螺卵囊高度平均为7.33 mm，卵粒数量平均为165粒；黄口荔枝螺的早期发育属间接发生型，受精卵呈椭圆形，卵裂为盘状卵裂；在卵囊内，胚胎发育包括卵裂期、囊胚期、原肠胚、膜内担轮幼虫、膜内面盘幼虫；幼虫发育包括面盘幼虫、后期面盘幼虫和匍匐幼虫。

We can not find any known domains in BEX1, but we notice that the C-terminus of it is similar to p75NTR-associated cell death executer, which is also highly expressed in brain and X-link. It may be a signaling adaptor molecule involved in p75NTR-apoptosis induced by nerve growth factor.

已有文献报道，在小鼠植入前的胚胎发育过程中Bex1基因在转录水平表达量发生变化，在出生后睾丸的发育过程中表达也有差异，说明这个基因与小鼠的发育相关。

The outside gill formed the three fingerlike, in the 22、23 stage, it developed at the peak, in the 25 stage, the operculum folded the outside gill in the operculum antrum, the inside gill formed, at the same time the outside gill degenerated.

外鳃进一步发育，形成了三排指状外鳃，到22-23期，达到发育高峰。到胚胎发育25期，外鳃被鳃盖包在鳃盖腔里面，内鳃开始形成，同时外鳃开始退化消失。

From April to September, several clusters of bamboos, 3 ~ 4 m long, 1 ~ 2 m wide, were set on the sea bed at a depth of 16 to 20 m to attract their spawning, and the egg-strings were then transported to the laboratory. When the development of the embryo reached stage 24, iris of eyes being prominent as a colour circle and statolith being formed, they were transferred into different rearing conditions, i.e., 20, 25, 30, 35 o/oo and 15, 20, 25, 30 oC. The durations from stage 24 to hatching were different among all different rearing conditions. The statoliths were extracted and mounted in Crystal Bond thermoplastic cement for reading their growth rings.

每年的四月到九月为东北角软丝主要的产卵季节，竹丛被设置在沙质海床上吸引成熟的个体前来产卵，将采集到的卵串带回实验室中培养，当胚胎发育至第二十四期的时候(胚胎的虹膜及平衡石开始生成)，这些胚胎分别被转换至不同的温度及盐度条件之下培养，温度被控制在15， 20， 25， 30 oC 四种条件下，盐度则分为20， 25， 30， 35 o/oo 四种条件，共组成十六种不同的培养条件，从平衡石生成至幼体孵出所需要的时间随著培养条件的不同而有所差异，孵化所需要的时间会随著培养的温度而有很大的变化，低温的条件会将所需的时间增长许多，在正常的条件下(25oC，35o/oo)，从平衡石出限制肤出约需要9~16天。

After transfer of 13 twin blastocysts to recipients, 3 and 2 twin fetuses were obtained, These findings indicate that monozygotic twin mice can be produced more efficiently from F1 embryos than from CD-1 embryos.

在添加生长因子与未添加生长因子的胚胎中，分别有92％和86％的胚胎发育为孪生囊胚。13对胚胎移植后，分别产生了3对和2对孪生小鼠。

These ES cells were introduced into host embryos from outbred KMW though blastocyst injection. Using GFP, the attractive genetic marker, we have been able to follow the fate of ES cells in living embryos and to observe directly the contribution of these cells to mouse embryos. Totally, four GFP-expressing 'green' chimeric mice expressing GFP were obtained.

为研究嵌合体动物中供体胚胎干细胞在宿主胚胎发育中的走向和定位，同时探讨绿色荧光蛋白基因作为报告基因在转基因动物制作中的应用价值，本研究将pEGFP-N1基因导入小鼠ES-D3细胞系，得到稳定表达GFP的胚胎干细胞亚系ES-D3-GFP，通过对昆明小鼠的囊胚腔注射，获得了4只表达绿色荧光蛋白的嵌合体小鼠。

Thirdly, we incubated the gene/ liposome complex with sperm, then artificially inseminated, and 53 of 357 embryos had fluorescence.

PCR检测得到的胚胎，发现表达绿色荧光蛋白的胚胎其PCR反应阳性率为100%，说明外源基因在胚胎发育早期可以表达。

In the present study, we collected cumulus cells oocyte complex from ovaries of two different strain mice. The cumulusenclosed oocytes were cultured for 6 h in MEM supplemented with growth factor and FSH. The meiotic maturation of these oocytes has progressed to pro-metaphse Ⅰ stage and the condensed chromosomes are visible under DIC microscope, metaphase Ⅰ spindle even can be detected under Polscope. The metaphase Ⅰ spindles of oocytes were exchanged under such microscopes. After electric stimuli, 91. 6% and 91. 6% karyoplasts-cytoplasm pairs were fused respectively. The resulting oocytes were cultured further in MEM and over 80% of oocytes released the first polar body. 79% and 77% of oocytes formed two pronuclei after in vitro fertilization and the embryos were cultured in KSOM supplemented with amino acids. Over 60% of embryos developed to blastocyst stage.

在本研究中我们在取得两种不同品系小鼠的卵丘卵母细胞复合体后，先将卵丘卵母细胞复合体置于含有多种生长因子和激素的MEM培养液中培养6小时，此时卵母细胞已进入第一次减数分裂的前中期，并且在DIC倒置显微镜下可以看到浓缩的染色体，用Polscope可以发现明显的纺锤体，借助这种显微镜通过显微操作将两种不同品系小鼠来源的卵母细胞的MI纺锤体进行互换，经过三次直流电脉冲作用后，分别有91.6％的胞质—MI核质体对融合，经过进一步的培养后，超过80％的重组卵母细胞排出第一极体，体外受精后分别有79％和77％的重组卵形成双原核，受精后的胚胎在KSOM胚胎培养液中体外培养4天后，超过60％的胚胎发育至囊胚。

Lab.of Genetics and Breeding of Crop,South China Agr.

本文以单胚水稻IR36作为对照，系统观察了多胚水稻品系APⅣ的胚胎发生过程，包括胚囊的形成、发育、受精及其胚胎发育；。。。

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