二倍体

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastcysts fellowed by fusion of cytoplasm and nucleus and cleavage in vitro.After fusion of cytoplasm, the DNA methylation levels of the fused embryos was very high as well as two-cell diploid embryos in vivo.Then the embryos was rapiddly demethylated when the nucleus begin to fuse, resulting the lowest DNA methylation levels when the nucleus fused completely.After that, the DNA methylation levels of fused embryos were gradually increased until the blastocysts stage.However, whereas an asymmetric distribution of DNA methylation was established in an vivo-derived blastocysts with a higher methylation level in the inner cell mass than in the trophectoderm, in most vitro-derived tetraploid blastocysts, we can not detect the asymmetric distribution.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在囊胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

If 〓mRNA positive expression, its DNA heteroploid type display as triploid or hypodiploidy, if 〓mRNA negative expression, its DNA heteroploid type display as hyperdiploidy、tetraploid or Bistem line. These from one flank demonstrate the role of 〓 gene suppress the proliferation of malignant tumor

表达阳性者，其DNA异倍体主要表现为三倍体或低二倍体，〓表达阴性者，其DNA异倍体主要表现为高倍体、四倍体和双干系，从一个侧面显示出〓基因的抑制恶性肿瘤细胞增殖的作用。

Tetraploid organisms may arise by the fusion of two diploid gametes that have resulted from the nondisjunction of chromosomes at meiosis, or by nondisjunction of the chromoosomes during the mitotic division of a zygote.

四倍体的产生可能是由于两个二倍体配子发生融合，这种二倍体配子又是在减数分裂中染色体不发生分离而形成。四倍体也可能因为受精卵进行有丝分裂时染色单体未发生分离而形成。

Result: The percentage of hyperdiploid cells, DNA Index and proliferative index were statistically higher in the vascular and the syncytial subtypes of meningioma than those in the fibrous and mixed subtypes, Also those in the severe edema group were higher than those in the moderate, mild and without peritumoral edema groups. The DNA hyperdiploidy were mostly found in the group of giant size tumor, DI and PI in the recurrent menigioma group were significantly higher than those in the nonrecurrent group.

结果：血管型、合体型脑膜瘤超二倍体率、DI和PI显著高于纤维型及混合型；重度水肿组DI、超二倍体率和PI显著高于中、轻及无水肿组；大肿瘤超二倍体率和DI均显著高于中、小肿瘤；复发性脑膜瘤的DI、PI均显著高于非复发组。

Diploid species and hexaploid, octoploid species of triticeae had remarkable differences in micro-morphological characteristics of pollen grain and stomata. However, some differences between hexaploid species and octoploid species were not significant.

可见，小麦族二倍体物种与六倍体物种、八倍体物种在花粉粒和气孔的微观特征方面有明显差异，但六倍体和八倍体物种之间差异不明显。

Diploid, triploid, tetraploid, pentaploid and hexaploid hybrid plants have been recovered from protoplast fusion, among which the tetraploid ones accounted for almost90%.

这些体细胞杂种有二倍体、倍体、倍体、倍体和六倍体，但主要是四倍体。

Results showed that the PMC meiosis of autotetraploid was similar to the diploid except some particularities. In metaphase Ⅰ, multivalent, quadrivalent, trivalent, bivalent and univalent were observed and some of the chromosomes were found not to rank on the metaphase plate and so did in metaphase Ⅱ cells. In anaphase Ⅰ and anaphase Ⅱ cells, there were lagging chromosomes, chromosome bridge and fragment. During anaphase Ⅱ and telophase Ⅱ, chromosome segregation was not synchronous or equal. At tetrad stage, dyad, triad, tetrad with micronucleus and polyad appeared.

结果表明，同源四倍体花粉母细胞减数分裂过程与二倍体相比，中期Ⅰ染色体构型复杂，有多价体、四价体、三价体、二价体和单价体；中期Ⅰ及中期Ⅱ有部分染色体没有排列在赤道板上；后期Ⅰ及后期Ⅱ出现落后染色体、染色体桥及断片；后期Ⅱ和末期Ⅱ有染色体不同步分离及不等分裂的现象；四分体时期还出现二分体、三分体、含微核的异常四分体及多分体。

Pollen activity of trisomic 2,7,9 was lower than that of diploid significantly;Pollen activity of trisomic 7 was the lowest.

5.9号三体的花粉活力显著低于二倍体；2号、7号三体的花粉活力极显著低于二倍体；7号三体的花粉活力最低。

The improved L.D.Cua method was used to induce tetraploid of Trichosanthes kirilowii Maxim. The suitable treating time of 0.2% colchicine, the morphology characters and cytology identification between plants of diploid and obtained tetraploid were studied.

采用改良L.D.Cua法诱导短把栝楼获得四倍体，研究了0.2%浓度的秋水仙碱诱导短把栝楼染色体倍性变异的最佳处理时间、四倍体栝楼与原栝楼的形态特征及其四倍体与二倍体的细胞学鉴定。

PCR amplification of di-, tetra- and hexaploid materials using genome-specific primers indicated that the NUMT inserted in the nucleus when the tetraploid wheat speciated or after that time and retained until the hexaploid wheat speciated.

用基因组特异引物扩增二倍体、四倍体和六倍体小麦，结果表明该插入事件发生在四倍体小麦形成时或形成后，并且一直保留到六倍体。

What would he tell Judith and the children?

他将怎样告诉朱迪丝和孩子们呢？

I this is at that time, the opinion with peacockish true girl is full of in a heart.

这就是当时的我，一个心中布满虚荣的女孩子真实的想法。