减数分裂

Tic division of F1 hybrid was normal ,anucleate cells and cells with micronuclei which were produced by asymmetrical separation of chromosomes were observed at the second meiotic division.

结果表明，杂种F1减数第一分裂基本正常，在减数第二分裂观察到由于染色体不对称分离产生的无染色质和仅带有微核的子细胞。

The sterile pollens were very concerned with non-equality of homologouschromosomes at two polars,and the difference of pollen yields among individuals werelikely related with disintegration of Tapetum in Prophase I.

其中败育花粉的产生与同源染色体的不均衡分配关系最为密切，而花粉产量的差异则可能是在减数分裂前期I时即发生绒毡层解体而造成的，其根源仍在于毛白杨染色体的异源性，此外易位、倒位等染色体结构变异和天然三倍体的存在也常常会加剧人们对毛白杨配子败育严重的印象。

Pig oocytes cultured in vitro for some time were inseminated by frozen–thawed ejaculated sperm. At specified times after insemination, sperm penetration, cell cycle progression and mitogen-activated protein kinase phosphorylation were evaluated. It was shown that:(1) oocytes at various maturational stages could be penetrated by sperm;(2) sperm penetration did not affect meiotic cell cycle progression;(3) sperm penetration of germinal vesicle oocytes and maturing oocytes did not alter MAPK phosphorylation; and (4) when premetaphase I and metaphase I oocytes, in which MAPK was activated, were fertilised, no evident MAPK dephosphorylation was detected as in metaphase II oocytes.

不同成熟阶段的猪卵与精子融合后体外培养发现：(1)不同成熟阶段的猪卵母细胞都可被精子穿透；(2)精子穿透不影响减数分裂细胞周期进程；(3)精子穿透GV期卵母细胞和正在成熟的卵母细胞不改变MAPK磷酸化：(4)已受精的前中期I和中期I卵母细胞的MAPK有活性，MAPK不像MII卵母细胞那样受精后发生磷酸化。

The results showed that after 2 h of culture in MEM the chromosomes of oocyte were seperated to form telophase I while a small spindle was observed around chromosomes of primary spermatocyte. However, two clear spindles were observed in the oocytes cultured in CB containing MEM. After further culture, the chromosomes of both primary spermatocyte and oocyte intermingled and formed one large spindle.

在无CB的培养液中培养的卵母细胞培养2小时后，卵母细胞已经进入第一次减数分裂的后期，染色体开始被拉向两极，而精母细胞的MI纺锤体才刚刚形成，虽然继续培养两者染色体可以合二为一并形成一个纺锤体，但是有些染色体发生滞后；当卵母细胞在含有CB的培养液中培养2小时后，在卵母细胞内形成两个相似大小的MI纺锤体，进一步培养形成一个大的纺锤体，染色体正常。

In meiosis I, homologous chromosomes pair up and line up in pairs at the centre of the cell.

在第一次减数分裂时，同源染色体成双地在细胞中间排列。

The separation of homologous chromosomes during meiosis.

在减数分裂过程中同源染色体的分离。

The failure of homologous chromosomes to pair during meiosis.

不联会在减数分裂期间同源染色体不联会成对。

There was an surge expression of MOS before germinal vesicle breakdown and at the same time began to disperse towards cytoplasm.

c-mos基因在动物卵母细胞减数分裂调控中起作用，但其作用机制目前仍不清楚。

Germinal vesicle breakdown is taken as the sign of oocytemeiotic resumption.

以生发泡破裂作为卵母细胞减数分裂恢复的标志。

PKA activators such as cAMP, 8 - Br -cAMP or phosphodiesterase inhibitor isomethyl butyl xanthine or purified PKA catalytic subunit all can inhibit germinal vesicle breakdown and meiotic maturation in mouse oocytes, also in Xenopus oocytes.

以小鼠卵母细胞为实验对象，给予PKA激动剂cAMP、8-Br-cAMP或磷酸二酯酶抑制剂IMBX均可抑制小鼠卵母细胞的胚泡破裂及减数分裂成熟。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。