精子发生的

It is revealed that the aberration of sex chromosome causes the most serious spermatogenesis failure and some breakpoints of autosome may also affect spermatogenesis.

由此可见，性染色体数目和结构异常是精子发生障碍的主要原因，其次常染色体的某些断裂点也可能影响精子发生。

In addition, using RT-PCR to detect expression of centrin homogene during Urechis unicinctus spermatid deferentiation and early embryonic development. The result revealed that (1) expression of HsCEN1 homogene is present during spermatid defferentiation including spermtid and sperm, but not in adult tissues including body wall tissue,intestinal mucous memberane cells and cell in coelom succus;(2) expression of HsCEN1 homogene is not present in unfertilized oocytes but present in that of released polar bodies after fertilization and parthenogenesis oocytes treated with A23187;(3) expression of HsCEN1 homogene is present during early embryonic development including two-cell stage,multicell stage,gastrula to trochophora.

我们还用RT-PCR方法检测了Centrin同源基因在单环刺螠精子分化过程和早期胚胎发育过程的表达，结果显示：在单环刺螠精子发生过程中的精细胞、精子团、精子中都有表达，而在成体的体壁组织、消化道组织、体腔球中则没有表达；在未受精卵中没有表达，而在受精后释放极体的受精卵和经A23187孤雌激活的卵中则有表达；在单环刺螠的早期发育过程——二细胞胚胎、多细胞胚胎、原肠胚、早期担轮幼虫——中都有表达。

SRG-L protein wasmainly observed in diplotene/pachytene spermatocytes, round and elongating spermatids.We can conclude this gene was activated during the early stage of meiosis, andtranscription of it kept high level during spermiogenesis.

因此初步判断这个基因在减数分裂早期被激活，转录在整个精子形成期维持较高水平的表达，有可能在精子发生后期起特殊作用，与减数分裂和精子变态成形相关。

Genes important for male gametogenesis involved in highly con-served landmark events such as meiotic recombination, formation of the synaptonemal complex, sister chromatid cohesion, spermiogenesis during postmeiotic stages, and checkpoints and factors required for the meiotic cell cycle .

精子发生中的重要基因与一系列精子发生过程中阶段性的细胞事件密切相关，例如减数分裂重组、联会丝复合物的形成、姊妹染色体的结合、减数分裂后精子的变态以及减数分裂周期中的关键点和必需因子等。

Some proteins change their affinity to the given DNA fragment depending on spermatogenesis. It suggests that the NM-L-IF is the most important in the condensation and remodeling of the sperm nucleus and in the morphogenesis of spermatids.

精子发生中NM-L-IF的形态结构、蛋白组成及与DNA的相互作用发生显著变化，这可能与精子细胞核的浓缩变形以及形态发生密切相关。

The reproductive toxicity of Aroclor 1254 on the oogenesis, the fertilization and preimplantion embryonic in vivo in female mice, the spermatogenesis toxicity, the sperma fertilizing ability and the zygote developmental toxicity in vivo in male mice were studied, and the toxicity mechanism were discussed by histopathological examination of the ovary, the uterus, the testis and epididymides.

以小鼠为动物模型，研究了类二噁英多氯联苯的典型代表物质——Aroclor 1254对母鼠卵子发生、受精和附植前胚胎体内发育毒性，公鼠精子发生毒性，以及对精子受精能力和受精卵体内发育的毒性。

The results show:(1) In testis, PNA receptors sites were firstly observed in the cytoplasm and plasma membrane of primary spermatocyte, and greatly increased in the plasma membrane of second spermatocyte, then decreased and were accumulated in the tail of the round spermatid. The same reaction was observed in sperms of testis and spermatheca, which shows stronger reaction in head and weaker in tail. A universal dyeing was observed on the plasma membrane of sertoli cells.

结果表明：(1)在中华蚱蜢的精子发生中，PNA受体是由初级精母细胞合成，然后转移到膜上，在次级精母细胞，由于量的积累其质膜出现了强阳性标记；从早期精子细胞到成熟精子时期糖蛋白的分布发生了明显的修饰变化，这些变化与精子获得与卵子进行识别、粘附、结合等受精能力密切相关：受精囊内与精巢内的精子表面的标记是相同的，说明质膜糖蛋白的修饰作用在精巢内就已完成。

According to the changes of the structure of chromatin and the morphology of cell, the process of the typical spermatogenesis of Cipangopaludina chinensis can be divided into five stages: spermatogonium, primary spermatocyte, secondary spermatocyte, spermatid and mature sperm.

中国圆田螺典型精子发生时，根据染色质和细胞形态的变化，可将其发生分为以下五个时期：精原细胞、初级精母细胞、次级精母细胞、精细胞和成熟精子。

Microdeletion of AZF gene is one of the causes leading to azoospermia and severe oligozoospermia, which has a close relation with the development of sperm defect.

AZF微缺失是引起特发性无精子症和重度少精子症的原因之一，与男性精子缺陷发生密切相关。

The sperm motility, the ultrastructure of spermatozoa and spermatogenesis were also studied.

并研究了斜带石斑鱼的精子活力，精子发生和精子超微结构。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。