细胞分裂

On the morphological differentiation,by inducing of fetal calf serum,it wasshown that the cytotrophoblast cells underwent aggregation first,and the adjacentcytoplasm membranes became tightly contacted through desomosomes andcytoskeleton.Then the adjacent cytoplasm membranes disintegrated fragmentallyto form fusion pore-like structure.Finally the multinuclear cells formed and inwhich the intercellular desmosomes disappeared.Immunocytochemical stainingfurther demonstrated that the formation of syncytium was through cell membranefusion rather than the amitosis process.

细胞形态分化的研究结果表明：早孕胎盘来源的细胞滋养层细胞在血清诱导下，首先发生聚集，并通过桥粒和细胞骨架使相邻的细胞膜紧密接触；之后细胞膜发生片段断裂，形成融合孔样结构；细胞间桥粒消失，最终形成多核的合体细胞；免疫细胞化学分析进一步证实合体化是通过细胞膜融合而非无丝分裂（amitosis即细胞核分裂而细胞质不分裂）实现的。

The two neck cells of the archegonium divided to fo rm four neck cells before fertilization, this division happened prior to the div ision of the central cell, but at times they divided synchronously.

颈卵器的2个颈细胞在受精前进行一次斜向分裂形成4个颈细胞，此分裂一般早于中央细胞的分裂，偶尔也可见颈细胞和中央细胞同时分裂。

To investigate whether the expression of cdc2 and cyclin B1 in spermatogenic cells during spermatogenesis is actually a temperature dependent event, in situ hybridization, Western blotting and immunohistochemistry analysis were used to study the expression of cdc2 and cyclin B1 in normal and cryptorchid testis. Results showed that heat would differentially hurt male germ cells in different developmental stages during spermatogenesis, especially the pachytene primary spermatocytes. Most of spermatogonia in contralateral cryptorchid testis were not harmed fatally by heat as yet, indicating that spermatogonia could resist to beat to a certain extent. In this case spermatogonia could develop to pachytene/diplotene primary spermatocytes, but they could not acquire the ability to complete the transition from mitosis to meiosis, and then appeared to go through apoptosis. Therefore, we could not find the descendants of meiosis: secondary spermatocytes and round spermatids, elongated spermatids and spermatozoon. The abdominal temperature had no significant influence on the transcription of cdc2 and cyclin B1 in the spermatogonia and pachytene/diplotene primary spermatocytes. In normal rabbit testis, cyclin B1 increased in the pachytene/diplotene primary spermatocytes before meiosis and reached its peak in the spermatids.

为了解精子正常发生过程中cdc2和cyclin B1表达的低温依赖性，我们利用原位杂交和免疫组化等方法，研究了正常和隐睾精子发生过程中cdc2和cyclin B1的转录和翻译调控活动，结果表明：（1）热对各阶段的雄性生殖细胞都有损害，粗线期的初级精母细胞尤为敏感，实验性隐睾内的精原细胞尚未完全受到"致命"影响，说明精原细胞对热有一定的耐受性，但即使成为粗线期／双线期初级精母细胞，却未能获得由有丝分裂过渡到减数分裂的能力，呈现不同程度的凋亡，所以在整个切片中找不到源自减数分裂的产物----次级精母细胞、圆形精子细胞，更谈不上长形精子细胞和精子的形成；（2）腹腔高温未明显地影响隐睾精原细胞和粗线期/双线期初级精母细胞中cyclinB1和cdc2的转录，说明高温并不是通过影响cyclin B1和cdc2的转录活动而导致生精过程阻断的；（3）正常兔睾丸组织中，〓在精原细胞和粗线期／双线期精母细胞中均有表达：cyclin B1蛋白在减数分裂前期的粗线期／双线期初级精母细胞中的表达量增加，于变态末期的精子细胞中达高峰。

The results implied that cell karyokinesis could be promoted at low concentration and be restrained at high concentration.

在一定低浓度条件下，蚕豆根尖细胞有丝分裂指数增高，高浓度下有丝分裂指数降低，意味着低浓度可促进细胞有丝分裂，高浓度则会抑制细胞有丝分裂。

The samples were smeared on slides and stained with Giemsas stain. The stained smears were observed microscopically and photographed. It showed that except typical trophozoites in binary fission. the following trophozoites of abnormal morphs were also observed. for instance abnormal trophozoites with binary fission; enlarged trophozoites with round and irregular shaped eosinophilic bodies in the cell plasma; enlarged cells containing round and irregular shaped eosinophilic bodies and flagella; enlarged cells which contain 6 or 8 nuclear-like bodies and flagella, 3 or 4 embryonic forms of daughter trophozoite in one mother trophozoite; 4 trophozoite embryonic forms with fused plasma 3 trophozoites with fused plasma;4 trophozoites with fused plasma; a pair of trophozoite with binary fission fused with another trophozoite;2 pairs of trophozoite with binary fission fused each other; a trophozoite with 1 nuclear only.

结果 除观察到典型的营二分裂法繁殖的贾第虫滋养体外，还可见到多种形态异常的虫体，包括；虫体呈非典型二分裂；滋养体胀大，胞质中有团块状和不规则形状的嗜酸性物质；在胀大的贾第虫细胞内含有团块状和不规则形状的嗜酸性物质以及鞭毛；在胀大的贾第虫细胞内含有6或8个核状物以及鞭毛；在一个母体细胞中含有3或4个子体细胞的雏形；胞质互相融合的4个滋养体的雏形；胞质互相触合的3个滋养体，胞质互相融合的4个滋养体；1对营二分裂的滋养体与另一个滋养休互相融合；2对营二分裂的滋养体互相融合；仅有1个细胞核的滋养体。

By the cooperation of 8-MOP/UVA, the photoaging-characteristic biological markers of the dermic fibroblasts in vivo and in intro were changed as follows:① with a permanent switch of mitotic to stably postmitotic phentypes, fibroblasts displayed growth suppression and morphological changes of cell senescence;② increasing expression of SA-β-galactosidase;③ increasing expression of p16 protein;④ continuous up-regulation of mRNA of MMP-1 and MMP-3, while the protein of TIMP-1 was only slightly induced;⑤ high levels of the 4977bp deleted mtDNA accumulated in dermis and cultured fibroblasts, and large accumulation of a A→C base transversion of 414 position of 〓 of human mtDNA control region for replication of cultured fibroblasts also.

2.8-MOP/UVA作用下，体内外真皮成纤维细胞生物学特性出现具有光老化特征性的改变：①细胞由具有分裂活性的分裂表型转化为不具有分裂能力的分裂后表型，形态学出现细胞衰老的相应改变；②SA-β-Gal表达增加；③p16蛋白表达增加；④MMP-1、MMP-3 mRNA持续表达而TIMP蛋白表达仅被轻微诱导；⑤mtDNA 4977bp缺失大量累积，培养成纤维细胞mtDNA复制控制区〓片段414碱基迅速出现大量A→C的点突变。

In conclusion, these results suggested that (1) the ageing-associated decline in fertility of female KM mouse was due to a decrease in both quantity and quality of oocytes;(2) the ooplasm from young mice did not correct the meiotic errors of aged mice, and the ooplasm from aged mice did not induce abnormal segregation of meiotic chromosome of young mice, indicating that meiotic anomalies found in the oocytes of aged mice might be related to nucleus or chromosomes and relevant factors;(3) a critical nucleocytoplasmic ratio was essential for normal maturation and segregation of meiotic chromosomes of oocytes and development to 2-cell embryos.

本研究结果表明：（1）昆明白小鼠与衰老相关的生育力下降是其卵母细胞数量减少和质量下降的综合结果；（2）年轻小鼠卵母细胞细胞质不能纠正老龄小鼠GV的减数分裂错误，老龄小鼠卵母细胞细胞质也不诱导年轻小鼠的GV发生减数分裂错误，老龄小鼠卵母细胞减数分裂异常很可能与细胞核或染色体及其相关因素有关；（3）关键的核质比对卵母细胞正常的成熟、减数分裂染色体分离及2-细胞期胚的发育是绝对必需的。

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 first split of microspore mother cell is observed after one week after beginning of temperature arised under high temperature but the split of secondary sporogenous cell doesn't be found. The split of secondary sporogenous cell is still found after one week but the first split of microspore mother cell is observed after 12d under low temperature. Formating speed of male gametophyte is affected by temperature.

在高温条件下，开始加温1周后即看到小孢子母细胞进行第一次分裂，未观察到次生造孢细胞的分裂；在低温条件下，1周后仍能看到次生造孢细胞的分裂，12d后才看到小孢子母细胞进行第一次分裂。

The methods of enzyme-linked immunosorbant assay were employed to detect endogenous contents of abscisic acid, indoleacetic acid, gibberellins (GA3, GA4) and cytokinins of immature embryos, embryonic and non-embryonic calli during culture process.

酶联免疫法测定不同培养时间后未成熟胚，以及由此诱导的胚性和非胚性愈伤组织，内源脱落酸、吲哚乙酸、赤霉素(GA3、GA4)和细胞分裂素(DHZR、IPA、ZR)含量。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。