不减数分裂

The mitotic error rate in cleavage stage embryos was proven to be higher than the meiotic aneuploidy rate and as a consequence, the genome of a single blastomere is not representative for the genome of the other cells of the embryo.

在卵裂期胚胎这种有丝分裂的错误率被证明是高于减数分裂的非整倍体错误率，因此，单个卵裂球的基因不能代表其他胚胎细胞的基因组。

The dominant male sterility was expressed normally in the new Taigu genic sterile wheat carrying the intergenomically translocated Ms2, and the female fertility mechanism in its male sterile plants was normal as well. Observation of the chromosome configuration at meiosis of pollen mother cells of the young ears of the sterile plants showed that they were euploid plants (2n=42). No configurations different from those of the Taigu geneic sterility gene located at the original locus were noticed of the Ms2 intergenomically translocated back into the common wheat.

所获携带易组Ms2基因的新型太谷核不育小麦其显性雄性不育特性表达正常，且雄性不育株的雌性可育机制正常，对不育株幼穗花粉母细胞减数分裂期染色体构型的观察可见其为整倍体(2n=42)，尚未发现回归普通小麦的易组太谷核不育基因与原位点的太谷核不育基因有不同的表型。

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。

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。

Based on principle of pollen abortion, utilizing tapetum of anther cell, mitochondria of tapetum, callose well, process of cell meiosis during formation process of pollen, we adopt genetic transformation to create plant male sterility, such as, exogenous cytotoxin gene, chaperones, anti-sense RNA, degradation of callose ahead of time, disturbing information intercommunion between mitochondria and nucleolus and affected development of pollen sporule by bacteria.

根据花粉败育的原理，利用花药细胞绒毡层、绒毡层线粒体、胼胝质壁、细胞减数分裂过程等花粉形成过程中的不同环节，采取外源细胞毒素基因、分子伴侣、反义RNA技术、提早降解胼胝质、扰乱线粒体与细胞核之间的信息交流和细菌影响花粉小孢子发育等策略，使花粉不能正常形成，从而产生不育花粉，达到产生雄性不育的目的。

The results showed that the cell wall organization during anther development failed to divide into inner-wall, middle and tapetum normally, and not to provide material, energy and information transfer for the development of pollen mother cells, resulting in the occurrence of abnormal pollen mother cells separatist period; thus which could not form a normal pollen grains which led to abortion.

结果表明，不育花药壁组织在发育过程中，没有分化形成正常的内壁、中层及绒毡层，不能为花粉母细胞的发育提供物质、能量和信息的传递，造成花粉母细胞在减数分裂期发生异常，不能形成正常的四分体，因而未能形成正常的花粉粒而导致败育。

The observation showed that sterile plants and fertile plants in the pollen mother cell stage is not very different, when microspore mother cells of male sterile plants enter meiosis period, it could form normal tetrad cell , tetrad cell is normal in early development stage, In the uninucleate microspore stage , tapetal cells were vacuolization, the microspores were extruded to the middle by tapetal cells.

本研究利用石蜡切片法，结合光学显微镜技术对樱桃萝卜核质互作雄性不育系的不育株和对应保持系可育株的花药发育过程进行细胞形态学观察，观察结果表明：不育株与可育株在花粉母细胞时期差别不大，不育株的花药小孢子母细胞进入减数分裂期后，可以正常的形成四分体，四分体前期发育正常，而在单核小孢子期绒毡层细胞出现液泡化，绒毡层细胞向中间挤压小孢子。

1Unequal number of univalents with decreased degree of synapsis and lagging chromosomes occurred in meiosis.The abnormal chromosomal behavior correlated with heterogenicity gave rise to unequal allocation of homogenous chromosomes to daughter cells and resulted in the deletion of functional chromosoms,thus led to the occurence of a certion proportion of aborted pollens.(2)The interaction between genetic imbalance and such environmental factors as temperature,etc.,further drew forth physiological and even structrural imbalance,with abnormal development of pollen mother cells and tapetal cells,and consequently resulted in no or very few production of pollens.The difference in the interaction between environment and genotype reflected on the unstability of pollen abortion in different years.

1在减数分裂中有数目不等的联合程度较差的单价体以及落后染色体出现，这种与异质性相关的染色体行为异常，导致同源染色体向子细胞的不均衡分配，造成具功能染色体的缺失，从而引起毛白杨一定比率的败育花粉的产生；(2)遗传上的不平衡与温度等环境因子相互作用，进一步引发毛白杨生理乃至结构上的不平衡，花粉母细胞和绒毡层细胞发育异常，从而造成不产粉或产粉较少；环境与基因型互作的差异性导致了花粉败育的年度不稳定性。

No tapetal cells were formed or tapetam collapsed at very early stage in some anther chamber during the microsporogenesis; Pollen mother cells in another chamber were not developed and microspore vacuolized; Tapetum cells developed abnormally, giantized and crammed the anther chamber; Some tapetum cells developed normally, but PMCs developed abnomally, which deformed at sporogeneous stage, and then were abhensive each other and finally degenerated. Nearly no PMCs could complete the process of meiosis, and form the tetrad, leading to the failure of normal microspore development.

药室的绒毡层细胞不形成或提前解体；药室内的花粉母细胞不发育或小孢子液泡化；绒毡层细胞发育异常，出现巨型化而挤满整个药室；绒毡层细胞虽发育正常，但花粉母细胞发育异常，在造孢细胞时期即开始出现变形现象，随后发生粘连退化；绝大部分花粉母细胞不能完成正常的减数分裂过程形成四分体，导致小孢子退化。

Pig oocytes cultured in vitro for some time were inseminated by frozen–thawed ejaculated sperm. At specified times after insemination, sperm penetration, cell cycle progression and mitogen-activated protein kinase phosphorylation were evaluated. It was shown that:(1) oocytes at various maturational stages could be penetrated by sperm;(2) sperm penetration did not affect meiotic cell cycle progression;(3) sperm penetration of germinal vesicle oocytes and maturing oocytes did not alter MAPK phosphorylation; and (4) when premetaphase I and metaphase I oocytes, in which MAPK was activated, were fertilised, no evident MAPK dephosphorylation was detected as in metaphase II oocytes.

不同成熟阶段的猪卵与精子融合后体外培养发现：(1)不同成熟阶段的猪卵母细胞都可被精子穿透；(2)精子穿透不影响减数分裂细胞周期进程；(3)精子穿透GV期卵母细胞和正在成熟的卵母细胞不改变MAPK磷酸化：(4)已受精的前中期I和中期I卵母细胞的MAPK有活性，MAPK不像MII卵母细胞那样受精后发生磷酸化。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。