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.

細(xì)胞形態(tài)分化的研究結(jié)果表明：早孕胎盤來源的細(xì)胞滋養(yǎng)層細(xì)胞在血清誘導(dǎo)下，首先發(fā)生聚集亚洲91网视频在线播放，并通過橋粒和細(xì)胞骨架使相鄰的細(xì)胞膜緊密接觸亚洲最大天堂在线观看视频；之后細(xì)胞膜發(fā)生片段斷裂，形成融合孔樣結(jié)構(gòu)www.尤物；細(xì)胞間橋粒消失性爽交刺激视频在线，最終形成多核的合體細(xì)胞；免疫細(xì)胞化學(xué)分析進(jìn)一步證實(shí)合體化是通過細(xì)胞膜融合而非無絲分裂（amitosis即細(xì)胞核分裂而細(xì)胞質(zhì)不分裂）實(shí)現(xiàn)的性爱在线欧美。

The ultrastructural changes during the development of sieve element companion cell complex (SE/CC complex) in Populus deltoides were investigated using electronic microscopy. The result showed that SE and CC tome from the same secondary phloem mother cell. The development of sieve element went through three stages, i. e. immature, mature, and degenerate stage. In immature stages the sieve element presented radial expansion, cell wall thickening, and production of sieve plastid and P-protein. The cytoplasma selectivly autolysed in mature stage. At the same time, karyoplasm was dispersed, and nuclear envelope was not clear, or karyoplasm was disorgnized, and nuclear envelope was clear. The karyopalsm finally turned into P-protein. In degenerate stage, the cytoplasm completely disappeared, and the function was lost.

利用電鏡技術(shù)研究美洲黑楊次生韌皮部篩管和伴胞發(fā)育過程中細(xì)胞超微結(jié)構(gòu)的動態(tài)變化成a免费视频大全，觀察到篩管和伴胞由同一個次生韌皮部衍生細(xì)胞分裂分化形成篩管約發(fā)育歷經(jīng)未成熟期、成熟期和衰退期的變化未成熟期篩管分子表現(xiàn)為細(xì)胞的徑向擴(kuò)展日韩看片自拍视频、壁的增厚欧美一级二级三级网站大全、篩管質(zhì)體和P-蛋白質(zhì)的產(chǎn)生；成熟期篩管分子細(xì)胞組分發(fā)生選擇性自溶色妞精品一级，細(xì)胞核核質(zhì)彌散狀曰韩一级无码AA特黄毛片，核膜不清晰，或核膜清晰而核物質(zhì)降解欧美性爱综合肏，最后細(xì)胞核完全解體轉(zhuǎn)化為P-蛋白質(zhì)類的物質(zhì)；衰退期篩管分子細(xì)胞質(zhì)完全解體消失国产黄片一区二区三区，失去功能中文字幕与子乱视频。

The two sperm nuclei and the tube nucleus are all derived from a single microspore nucleus by mitosis.

兩個精核和管核都是從同一個小孢子核有絲分裂產(chǎn)生的。

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?yàn)橛糜诩?xì)胞學(xué)檢測的小麥材料是擱置多年的陳舊種子成年男女a片免费看，所以在檢測染色體數(shù)目時官网视频在线欧美不卡中无图片高清日韩，發(fā)現(xiàn)大量異常分裂現(xiàn)象，包括染色體橋被爆操精品网站、染色體落后一本久道热线在线无码视频、微核、多極分裂等小草无码视频；實(shí)驗(yàn)過程中還發(fā)現(xiàn)小麥多花藥現(xiàn)象和花粉粒具雙萌發(fā)孔的現(xiàn)象黄色网站欧美；同時在顯微觀察同時還注意搜集了細(xì)胞有絲分裂、減數(shù)分裂各個時期的分裂相圖片美女屁股喷白水视频网站。

Reduction division The first division of meiosis , including prophase, metaphase I, and anaphase I. It results in a haploid number of chromosomes gathering at each end of the nuclear spindle.

減數(shù)分裂：減數(shù)分裂中的第一次分裂456在线视频，包括分裂前期，中期 I 和后期 I 老人黄色视频，形成單倍數(shù)目的染色體在每一個核紡錘體末端聚集三级毛片照片网站。

The cleavation rates and blastocyst development rates of cloned embryos were used to assess the efficiency of different operational procedure. Finally, the best combination of operational procedure, that the spindle-viewer system was used for oocytes enucleating, and donor cell was electrofused into ooplasm by electrical pulse (1.9 kV/cm, 10 ms, two) to reconstruct bovine cloned embryos.

以核移植胚胎的卵裂率、囊胚發(fā)育率作為檢測指標(biāo)凹凸在线导航AV网站，對不同的方法所獲得的克隆胚胎的卵分裂率與囊胚發(fā)育率進(jìn)行比較日韩美女精品一区二区，最后篩選獲得1個優(yōu)化的牛體細(xì)胞核移植操作程序全网免费看黄，即采用Spindle view系統(tǒng)對牛卵母細(xì)胞進(jìn)行去核操作，將供核體細(xì)胞注射到卵周隙v免费黄色视频，然后通過電融合法將供體核引入去核卵細(xì)胞質(zhì)(電融合參數(shù)為1.9 kV/cm又大又粗又黄的视频大全，脈沖時程10 ms，方波2次間隔2 s)影音先锋女人鲁色资源网。

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.

本研究結(jié)果表明：（1）昆明白小鼠與衰老相關(guān)的生育力下降是其卵母細(xì)胞數(shù)量減少和質(zhì)量下降的綜合結(jié)果日韩综合一区视频在线91；（2）年輕小鼠卵母細(xì)胞細(xì)胞質(zhì)不能糾正老齡小鼠GV的減數(shù)分裂錯誤，老齡小鼠卵母細(xì)胞細(xì)胞質(zhì)也不誘導(dǎo)年輕小鼠的GV發(fā)生減數(shù)分裂錯誤99久久大黄片，老齡小鼠卵母細(xì)胞減數(shù)分裂異常很可能與細(xì)胞核或染色體及其相關(guān)因素有關(guān)我要黄色网站；（3）關(guān)鍵的核質(zhì)比對卵母細(xì)胞正常的成熟、減數(shù)分裂染色體分離及2-細(xì)胞期胚的發(fā)育是絕對必需的在线看男女AV免费网址不卡。

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.

雄性細(xì)胞異常發(fā)育有幾種情況：小孢子母細(xì)胞強(qiáng)烈液泡化人人操黄色网，細(xì)胞質(zhì)收縮解體，不能進(jìn)入減數(shù)分裂中国一级操逼片；小孢子母細(xì)胞液泡化找一个av网站，雖能進(jìn)入減數(shù)分裂，但不能形成正常二分體而中途退化717影视午夜理论片大全福；二分體在线观看国产黄片视频、四分體細(xì)胞液泡化，不能進(jìn)行正常發(fā)育99re国产在线；單核小孢子中央期欧洲A∨国产在线，細(xì)胞質(zhì)收縮包圍核，小孢子形狀扭曲呈月牙形或不規(guī)則形色色色色色色色色色色69快射视频，最終細(xì)胞質(zhì)和核解體而呈月牙形的空殼小孢子特级大黄A片免费线观看网站；單核液泡期的小孢子不能積聚營養(yǎng)物質(zhì)，細(xì)胞質(zhì)解體而成為大的空殼花粉粒久久久精品久久久久。

Megaspore mother cells undergo meiosis, which results in the formation of 4 megaspores in a row. The chalazal-most cell develops into an 8-nuclei embryo sac after 3 rounds of mitosis. A mature embryo sac is produced after cellularization and nuclear migration.

結(jié)果表明：1大孢子母細(xì)胞經(jīng)過減數(shù)分裂形成直線排列的4個大孢子久久无码A片，其中珠孔端的3個大孢子退化，合點(diǎn)端的大孢子進(jìn)行3次有絲分裂九九性爱，形成八核胚囊在线不卡高清AV户外， 8個核迅速細(xì)胞化，最終發(fā)育為成熟胚囊欧美日韩区国产区。

For transgenic mice,98%~100% of metaphases and 85%~94% of interphases showed hybridization signal.For negative control mice,100% of metaphases and 95%~96% of interphases showed no hybridization signal.

陽性轉(zhuǎn)基因小鼠98%~100%的中期分裂相一级毛片试看三分钟，85%~94%的間期核出現(xiàn)雜交信號；陰性對照小鼠100%的中期分裂相a免费网站、95%~96%的間期核未出現(xiàn)雜交信號最新国产一区。