双核仁的

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。

While under natural low temperature (10-20℃), a great deal of abnormalities, including micro nucleoli, scattered and lagged chromosomes and anaphase bridges were detected during PMC meiosis, even though the abnormalities were different between the two cultivars; the ratio of micro nucleoli was 22.88% of average, which was obviously higher than that of control (4.56% of average under normal temperature); and the ratios of univalent and multivalent in diplotene, which increased seriously, were 8.82% and 17.65% of Tainong 1, and 14.52% and 24.19% of Irwin under natural low temperatures.

低温（10~20℃）条件下，减数分裂过程中核仁的行为发生大量异常，微核仁的平均检出率高达22.88%，明显高于常温条件下的平均4.56%；双线期单价体和多价体的发生频率有明显增加，其中台农1号为8.82%和17.65%，Irwin为14.52%和24.19%；减数分裂中期Ⅰ、Ⅱ及后期Ⅰ、Ⅱ均观察到落后染色体，其中台农1号异常率为12.73%、5.63%、15.79%和4.76%，Irwin为11.11%、7.61%、9.52和6.38%。

In the treatment of higher concentration of NaN_3,some cells appeared crystalloid,two nuclei,abnormal nucleus,nucleolus losing.

较高浓度NaN3处理的PLB细胞中出现晶体物质、双核、畸形核和核仁丢失等现象。

The ultrastructure characters of pollen grain in Brassica napus are:1There are vacuoles in cytoplasm but no starch grain in uniceelluar pollengrain.2The veget- ative nucleus of bicellular pollen grain is generally spheroidal;while the generative cell is spinde-shaped,with a big nucleus,thin layer of cytoplasmand few cell orgens,no cell wall.3In three-celled pollen grain the sperm cell is separated from the cytoplasm of vegetative cell by two layers of plasmic membrances.

Brassica napus的花粉粒，在不同发育时期超微结构的特征如下：1单胞花粉粒有一个球形的细胞核和明显的核仁，细胞质内出现液泡，缺少典型的淀粉粒。2双胞花粉粒的营养核多为球形。生殖细胞纺锤形，无细胞壁，细胞核比例大，细胞质呈薄层，细胞器少。3三胞花粉粒有一个裂片状的营养核和两个纺锤形的精细胞，精细胞无壁，以两层质膜与营养细胞的细胞质相隔。

RESULTS: After 24 hours of preinduction, cells changed from spindle to polygonal or irregular, with many short rod-shape processes and 2-3 nucleoli. Whirlpool shape growth disappeared, and was disordered. After 1-3 hours of induction, cells gradually became round, with significant cell contraction, strong refraction, bipolar or pluripolar processes connected each other into a net. After 5 hours of induction, grades one and two branches were detected.

结果：预诱导24 h，胞体由原来的长梭形变成多角形或不规则形，伸出多个短棒状突起，可见2~3个核仁，细胞间漩涡状生长趋势消失，排列无规律；诱导1~3 h，细胞逐渐变圆，胞质收缩明显，折光性增强，双级或多极的突起互相连接呈网状；诱导5 h，突起出现一、二级分支。

Furthermore, by using two-colored probes to study the relationships between RNA polymerase Ⅲ and RNA polymerase I, we observed that the signals of the two RNA polymerase were very close.

同时，应用这一研究方法对RNA聚合酶Ⅰ的转录发生在核仁中的结论进行了确证，并进而应用双探针标记荧光原位杂交的方法对RNA聚合酶Ⅲ和RNA聚合酶Ⅰ转录位点的关系进行了初步探讨，结果显示两者的转录位点之间非常接近，并且有伴随发生的趋势。

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。