胚胎发育

Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China on artificial activation and parthenogenesis in mammalian oocytes are reviewed, in-cluding oocyte activation and

综述了哺乳动物卵人工激活与孤雌生殖研究的主要进展，包括卵母细胞的激活与孤雌发育，父源和母源基因组在胚胎发育中的作用，以及孤雌生殖小鼠的诞生。

Different mediums should be exploi at the stage of embryo development to achieve the embryo maturation and plantlet formation.

需要在不同胚胎发育阶段变换使用不同的培养基，才能实现幼胚发育成熟和植株形态建成。

With the amplification of farming scale and increase of yield, a series of problems to be resolved urgently appear in production, for example: Bad ovary development of female crab, inclining egg-holding rate, high mortality of embryo development, low survival rate of juvenile crab, the shortage of good quality juvenile, precociousness of crab etc.

随着河蟹养殖规模的扩大、集约化程度和产量的提高，在实际生产中出现了一系列亟待解决的问题，雌蟹亲体的性腺发育不良、抱卵率下降、胚胎发育死亡率高、幼体育成率低、质优量足的苗种供应不足、河蟹性早熟等问题，都严重制约了河蟹养殖业的健康、稳步发展。

In mammals, testosterone synthesized by testis interstitial tissue play an important role in the physiological procedures such as malization of embryo development, production of sperm, male sexual behavior and male sex gland development.

在哺乳动物中，睾丸间质组织合成分泌的睾酮在胚胎发育的雄性化、精子的生成、雄性性行为以及雄性性腺的发育等生理过程中起着重要的作用。

Also the adolescent age's biology and physiology, and human's heritable disease, sex hygiene, sex transmitting

从生物学、生理学的角度，在讲述这门课开设的意义、性分化的生物学意义和人类生殖模式的基础上，简要讲述人类性行为的特点和进化，进而讲解男女生殖器官的基本结构与机能、性机能的生物学和生理学基础及其调节控制、人类受精、胚胎发育、生育、性的发育与分化以及青春期的生物学、生理学知识和问题，并讲述人类遗传病、性卫生、性传播疾病包括艾滋病的预防和控制等基本知识。

This course includes the basic structures and functions of Human's reproductive organs ; human fertilization ; development ; women's breeding ; sex development and differentiation. Also the adolescent age's biology and physiology, and human's heritable disease, sex hygiene, sex transmitting diseases will be introduced. Through this course students will understand themselves deeply.

从生物学、生理学的角度，在讲述这门课开设的意义、性分化的生物学意义和人类生殖模式的基础上，简要讲述人类性行为的特点和进化，进而讲解男女生殖器官的基本结构与机能、性机能的生物学和生理学基础及其调节控制、人类受精、胚胎发育、生育、性的发育与分化以及青春期的生物学、生理学知识和问题，并讲述人类遗传病、性卫生、性传播疾病包括艾滋病的预防和控制等基本知识。

Conclu sion:(1)Surface densities of PCNApositive cells reached their peaks on 14th day after birth,but the number of apoptotic cells reached its peaks on 21st day p ostnatal,so the apoptotic peak was late the proliferating peak for a week,and related to the particular period in cycle of seminiferous epithelium;(2)The spe rmatogium were found move from center to the periphery of the seminiferous tubule and arrange disorder to order;(3)The spermatogonium remained replicating activ ity of DNA during the developing stage.

生精细胞凋亡的高峰要滞后其增殖峰1周左右，而且与其所处生精周期的特定阶段有关；（2）精原细胞在胚胎发育过程中向曲细精管周边迁移，其排列由无序到有序；（3）在生后各发育阶段中，精原细胞始终保持DNA复制的能力。

These results suggest that ethanol be the major factor in dysfunction of brain development whereas acetaldehyde plays critical roles in other organ teratogenesis.

上述结果提示FAS中的脑发育异常是乙醇独立作用的结果，乙醛则引起FAS中的辅助畸形。关键词醇，乙乙醛胚胎发育胎儿酒精综合征联合作用

The cloning of mammals by somatic cell nuclear transfer requires epigenetic reprogramming of the differentiated state of donor cell to a totipotent, embryonic ground state.

由于供体核支持整个克隆动物的发育，所以当供体核被移入去核的卵母细胞后，必需进行重编程，回到胚胎发育的起始阶段。

Based in part on commonalities in embryonic development among all chordates, the tunicate brain is believed to resemble the evolutionary precursor of the vertebrate brainstem.

被囊动物的神经节和脊椎动物胚胎发育过程中大脑的发育有相似之处，被认为是脊椎动物

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。