减数分裂

Due to the deficiency of cyclin B1 and 〓, spermatogonia and pachytene/diplotene primary spermatocytes in contralateral cryptorchid testis were unable to form MPF, and therefore, they could not accomplish their nuclear division, and became arrested at the transition stage from mitosis to meiosis (G2/M phase). We also found that testosterone could regulate the cyclin B1 expression in spermatogenic cells.

由于cyclin B1和〓的缺失，粗线期/双线期初级精母细胞中的MPF无望形成，从而导致生精细胞分裂停滞在由有丝分裂向减数分裂过渡的G2/M相；（5）睾酮可在翻译水平上调控阴囊内睾丸生精细胞cyclin B1蛋白的表达。

The primary sporogenous cells divided into the second sporogenous cells which would turn into microspore mother cells in a microsporangium. The cytokinesis in meiosis of the microspore mother cells was of modified simultaneous type, forming the decussate, isobilateral or T-shaped tetrads.

初生造孢细胞分裂形成次生造孢细胞，次生造孢细胞再转化为小孢子母细胞，小孢子母细胞减数分裂的胞质分裂为修饰性同时型，四分体排列方式为交叉型、对称型或"T"型，成熟花粉粒二细胞型，开花时散出。

In this study, we performed sequential combined PI and DAPI staining and FISH with two different 45S rDNA clones on meiotic pachytene and mitotic metaphase chromosomes in tomato.

采用CPD染色对番茄减数分裂粗线期和有丝分裂中期染色体进行了显带分析，随后用两种不同的45S rDNA 克隆在相同的分裂相进行了荧光原位杂交定位分析。

Puna Chicory, leymus multicaulis and Psathyrostachysjuncea.For the materials used in this article were some old seeds which had been stored for 3-7 years, we found a lot of abnormal mitotic and meiotic cells, such as chromosome bridge. chromosome laggard, micronucleus, multipolar division and so on. Moreover, we also found the wheat"s multi-anther, double germinate-hole"s microspore and collected the photos of every period of meiosis. mitosis.

因为用于细胞学检测的小麦材料是搁置多年的陈旧种子，所以在检测染色体数目时，发现大量异常分裂现象，包括染色体桥、染色体落后、微核、多极分裂等；实验过程中还发现小麦多花药现象和花粉粒具双萌发孔的现象；同时在显微观察同时还注意搜集了细胞有丝分裂、减数分裂各个时期的分裂相图片。

Telophase The final stage in mitosis and meiosis, in which the separated chromatids or homologous chromosomes of bivalents collect at the poles of the spindle and the nuclei of the daughter cells are formed.

细胞分裂的末期：是细胞的有丝分裂和减数分裂的终极阶段。在这个时期内，分离的姐妹染色单体或二价体的同源染色体向纺锤体两极聚拢，同时子代细胞核形成。

General characteristics of cells, its chemical constituents ( protein, nucleic acid, carbohydrate, lipid), cell structure , cell cycle, cell division, four kinds of tissues (epithelial, connective, muscular, and nervous), organ, ten organ systems (dermal, skeletal, muscular, digestive, respiratory, circulatory, excretory, endosecretory, nervous, and reproductive).

细胞的一般特征，细胞的化学组成(蛋白质，核酸，糖类，脂类)，细胞的结构，细胞周期，细胞分裂(无丝分裂，有丝分裂，减数分裂)，四大组织(上皮组织，结缔组织，肌肉组织，神经组织)，器官，十大系统(皮肤系统、骨骼系统、肌肉系统、消化系统、呼吸系统、循环系统、排泄系统、内分泌系统、神经系统和生殖系统)。

The primary sporogenous cells divided into the second sporogenous cells which would turn into microspore mother cells in a microsporangium. The cytokinesis in meiosis of the microspore mother cells was of modified simultaneous type, forming the decussate, isobilateral or T-shaped tetrads.

初生造孢细胞分裂形成次生造孢细胞，次生造孢细胞再转化为小孢子母细胞，小孢子母细胞减数分裂的胞质分裂为修饰性同时型，四分体排列方式为交叉型、对称型或&T&型，成熟花粉粒二细胞型，开花时散出。

The testis index, testis volumes were same as the annual changes of testis mass. The curves of annual variation were all unimodality.2 The spermatogenetic cycle of Myospalax cansus comprises seven stages with significant features: Stage I , from February to April, the testis were at the stage of spermatogonia proliferation. In this period, testis index and the number of spermatogonia began to rise. Other spermatogenic cells had not yet formed; Stage II to III, from March to April, primary spermatocyte meiosis period. The testis index was highest in this stage, and spermatogenic cells were in spermatocyte stage, the primary spermatocyte meiosis generated to secondary spermatocyte; Stage IV, from April to May, spermatocytes continued to split, germ cells appeared in seminiferous tubules; Stage V, in May, sperm formation, spermatids of seminiferous tubules were transformed to spermatozoa, a large number of sperms existed in the lumen; Stage VI, spermatozoa emission period, from May to June, testis index were a significant drop and mature spermatozoa excluded gradually; VII, the testicular activity ceased basically from July to September, November to January of the following year, the spermatogenic activity ceased completely. Therefore, Myospalax cansus are animals of seasonal reproduction, spermatogenesis cycle is discontinuous type.

睾丸系数、体积和重量的年周期变化规律一致，变化曲线呈现单峰型。2甘肃鼢鼠雄性生殖腺的年周期活动由7个特征明显的时期构成：Ⅰ期，2～3月份，精原细胞增殖期，睾丸系数开始上升，精原细胞进行有丝分裂，其他生精细胞尚未形成；3～4月份为Ⅱ～Ⅲ期，初级精母细胞成熟分裂期，睾丸系数达到最大，生精细胞大多处于精母细胞阶段，初级精母细胞减数分裂生成次级精母细胞；Ⅳ期，4～5月份精母细胞继续进行分裂，精细胞在生精小管内出现；Ⅴ期，5月份，精子形成期，曲细精管中精细胞变态成精子，在管腔中存在大量的精子；Ⅵ期，精子排放期，5～6月份，睾丸系数显著下降，成熟精子从生精小管上脱离，逐渐排除；Ⅶ期，精原细胞停滞期，7～9月份睾丸生精活动基本停滞，11～翌年1月，生精活动完全停止。

The situation of abnormal development of male cells is as follows:microspore mother cell can't enter into meiosis because of intense vacuolation,shrink and disintegration of its cytoplasm;although vacuolated microspore mother cell can enter into meiosis,it can't form normal dyad and degenerate in the middle process;dyad and tetrad become vacuolated and can't develop normally;cytoplasm of microspore shrinks around the nucleus at the stage of central nucleus microspore,the shape of microspore is twisted into crescent or irregular shape,at last its cytoplasm and nucleus are disintegrated and crescent vacant microspore presents;nutritive substances can't be accumulated at the stage of vacuolated microspore,cytoplasm is disintegrated,and microspore turns into a big vacant pollen.

雄性细胞异常发育有几种情况：小孢子母细胞强烈液泡化，细胞质收缩解体，不能进入减数分裂；小孢子母细胞液泡化，虽能进入减数分裂，但不能形成正常二分体而中途退化；二分体、四分体细胞液泡化，不能进行正常发育；单核小孢子中央期，细胞质收缩包围核，小孢子形状扭曲呈月牙形或不规则形，最终细胞质和核解体而呈月牙形的空壳小孢子；单核液泡期的小孢子不能积聚营养物质，细胞质解体而成为大的空壳花粉粒。

The results showed that the varieties and activity of POD isoenzyme expression exist in difference in anther of male sterility line and maintainer in different development stage in sweet pepper and hot pepper. POD isozyme activity of anther was very low in meiosis stage in male sterility line of sweet pepper. There is a POD special band in meiosis and pollen mature stage in male sterility line of pepper respectively.

结果表明不育系与保持系，在花药发育的不同时期POD同工酶表达种类及表达活性之间存在差异，其中甜椒不育系在减数分裂期POD同工酶的活性非常低，辣椒雄性不育系在减数分裂期及花粉成熟期分别多一条POD特征带。

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。