精母细胞

Centromeres could be identified easily on the bivalents at diplotene, so it was convenient to analyse the karyotype.

结果表明，日本沼虾染色体数n=52，2n=104，据双线期二价体的相对长度、着丝点位置以及形态诸方面的特点分析了核型，共分为A，B，C，D4个染色体组，核型组成是N=37M+4ST+11T；初级精母细胞减数分裂前期I可分为细线期/偶线期、粗线期、双线期和终变期5个时期，双线期的二价体存在弥散阶段，核仁明显，且双线期二价体着丝点清晰，给核型分析带来了方便。

The results as follows: Chromosomal axial cores formed during leptotene nuclei in spermatocytes of the brown rat, some homologous axial cores were close to each other. The fomation of SCs starts at zygotene, completed at pachytene and disintegrates at diplotene.

在褐家鼠精母细胞的细线期，常染色体轴心（Axial cores， ACs ）已形成，同源轴心在空间上靠近，偶线期SCs 开始形成，到粗线期SCs 完全形成，于双线期SCs 开始解体。

To elucidate the relationship of GSE expression and gametogenesis, mRNA (0.5μg each) from mouse testis and ovary on different postnatal days were analyzed by RT-PCR with specific primers for GSE cDNA. The GSE mRNA in the testis of mouse was first detected at Day 14 postpartum, when cells at mid-pachytene are likely to appear.

为了阐明GSE表达与配子发生的关系，从0～49日龄小鼠睾丸和卵巢中提取mRNA（每样品0.5μg，将其与特定的GSE cDNA引物进行RT-PCR反应，分析的结果发现，GSE mRNA在出生后第14天的小鼠睾丸中首先被检测到，这一时间正是中粗线期精母细胞很可能出现的时期。

The test results of micronucleus and chromosome aberration in mice were all negative.

小鼠骨髓多染红细胞微核试验和小鼠睾丸精母细胞染色体畸变试验均为阴性。

The spiny eel , belonging to Perciformes, Osteichthyes, is a kind of little freshwater fish distributed in Southern China. In 1998, Our lab detected XX/XY differentiated sex chromosomes in this specie with karyotypic analysis, and then with chromosomal binding and SC observation, we identified that its two largest metacentric chromosomes were X, Y sex chromosomes in 1999. X, Y chromosomes differ each other not only in the distribution of heterochromatin but also in their shapes, which make them could be recognized directly under the light-microscope without any banding treatment.

刺鳅，属鲈形目、刺鳅科(Perciformes，Mastacembelidae)，是广泛分布于中国南方的小型淡水鱼类。1998年，我室通过核型分析，首次发现该物种具有明显分化的异形性染色体，其性别决定类型为XX／XY型。1999年，本室通过染色体显带、精母细胞联会复合体观察，再次确认刺鳅染色体组中最大的一对中部着丝粒染色体为X、Y性染色体，两者不仅已经出现结构异染色质分布上的不同，同时在外部形态上也存在明显差异，识别特征鲜明，在光镜观察下无需显带即能清晰辨认性染色体。

In the last EXP, the testis development during the first mature and the ultrastructure of spermatocytes of were studied. The process of spermatid formation was described.

试验四研究了泰山螭霖鱼精巢在第一次性成熟过程中的发育规律和各级精母细胞的超微结构。

The results of the early spermatid micronucleus test inmice for avermectin B1 by both above-mentioned methods were all negative.

于接毒后第6h和14h取材、制片、C-带染色，所观察到的小鼠次级精母细胞染色体畸变分析试验结果均为阴性。

RT-PCR results of LCM showed that it's expressed in the primary and secondary spermatocyte.

激光显微切割RT-PCR结果显示Cklfsf1表达于睾丸组织的初级和次级精母细胞。

One secondary spermatocyte divides and eventually grows into two sperm cells.

一个次级精母细胞分裂并最终产生两个精子。

With cysteamine pre-treatment, decreased yields of dominant lethals were obtained in spermatocytes, spermatids and in spermatozoa

用半脘氨预先处理，在精母细胞，精子细胞和精虫内均可使显性致死突变值下降。

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。