染色体

Somaclonal variations analysis on mixoploid hybrid plant BI-1 showed that percentage of cells with 2n=25, 26 decreased and percentage of cells with 2n=29 ascended.Chromosome segments of I.

并对混倍体杂种BI-1的无性系变异进行了分析，发现染色体数目为25、26的细胞比例呈明显下降趋势，而染色体数为29的细胞比例明显上升，其他染色体数目的细胞比例处于动态变化之中。

In the offsprings of the aneuploids (P3) with 41~44 chromosomes, there are four types of plants with 29~32 chromosomes. Except the plant with 29 chromosomes, others which appeared abnormal meiosis behavior and poor pollen fertility are mixoploid.

在染色体数为44与41的两种超倍体（P3群体）后代，鉴定出具有29~32条染色体的4种非整倍体，除染色体数为29的植株外，其余均为混倍体，它们的减数分裂异常，花粉育性低。

The single Y chromosome of Muntiacus reevesi and Y1,Y2 ,X+4,1 chromosome of Muntiacus crinifrons were obtained by flow-sorting ,then they were amplified through DOP-PCR .

以流式细胞仪分离小麂Y染色体和黑麂Y1，Y2，X+4和1号染色体，利用DOP-PCR技术富集了分离的各单条染色体。

Majority of acute leukemias in infant, either acute lymphoblastic leukemia or acute myeloblastic leukemia, posses a chromosomal translocation affecting the 11q23 chromosome region which specifically inoles the mixed-lineage leukemia gene.1-3 Most pediatric leukemias with MLL rearrangement clearly hae a remarkably short latency.1,4 MLL gene rearrangement is also associated with secondary leukemias of patients preiously treated with the topoisomerase II inhibitors.4 The latency of these secondary leukemias is similarly ery short.4 Of note, the concordance rate of leukemia with MLL rearrangement in infant monozygotic twins approximates to 100%,1,4 and identical breakpoint in the MLL gene was shared in these pairs of identical twin infants with concordant ALL.1,4 Moreoer, the unique and clonotypic MLL fusion gene was detectable in neonatal blood spots for Guthrie cards from non-twined indiiduals who subsequently deeloped ALL.1,4 These obserations indicate not only that MLL fusion is generated in utero but also that MLL fusion proteins could be capable of inducing leukemic transformation with few, if any, secondary mutations.2,3,4 Greaes et al speculate that an MLL fusion protein somehow promotes rapid transition to full-blown disease in patients ia ery rapid clonal expansion, genetic instability, or inhibition of DNA damage repair.4 In general, for clonal expansion of malignancies, tumor cells often hae acquired strategies that escape immune sureillance of the hosts.5,6 Immune escape mechanisms also contribute to the failure of graft-ersus-leukemia effect after allogeneic hematopoietic stem cell transplantation.7 Therefore, leukemia cells could acquire some immune escape mechanisms during leukemogenesis.

绪论 绝大多数的婴儿白血病，不管是急性淋巴性白血病或是急性骨髓性白血病，在染色体11q23部位有染色体易位的情况；这个部位的染色体易位牵连了混合谱系白血病基因。大多数具有MLL基因重排的儿童白血病潜伏期明显短很多。MLL基因重排也和经拓扑异构酶II抑制剂治疗后的继发性白血病有关。这些继发性白血病的潜伏期类似地都非常的短。很重要的是，单卵双胞胎婴儿同时患有或同时免于MLL基因重排阳性的白血病的一致性接近100%；并且同样患有ALL的同卵双胞胎的MLL基因的断裂点是一致的。而且，这种独特的克隆特异性的MLL融合基因能够从那些得ALL的非双生个体出生时的血斑标本中检测到。这些发现表明MLL融合基因产生在胎儿还在子宫的是后，而且MLL融合蛋白能过和其他的基因突变一起诱导白血病的产生。Greaes 等推测MLL融合蛋白在某种情况下同过快速克隆增殖，遗传的不稳定性或是DNA损伤修复的抑制促使疾病迅速地全面爆发。恶性肿瘤细胞的克隆增殖通常已经获得了逃避机体免疫监视的能力。免疫逃避机制也归因于异体外周血干细胞移植后移植物抗白血病作用的失效。所以，白血病细胞在白血病的产生过程中可能获得了某些免疫逃脱机制。

Photosynthetic traits of Ningai 1 and its 4B-monosomic, nullisomic line were investigated in this paper(Rht3 gene was located in 4B-chromosome). 4B-chromosome has the positive effects on photosynthetic rate, chlorophyll content, RuBP carboxy lase content and activity, leaf conductance, chlorophyll relatve steady phase and photosynthetic avtive duartion and these effects are accumlative. So 4B-chromosome has the promoting influence on photosynthesis.

本文系统地研究了带有Rht3基因的4B染色体二体(宁矮1号)、单体(宁矮1号M4B)、缺体(宁矮1号N4B)材料的光合特性，发现带有Rht3基因的4B染色体对光合速率、叶绿素含量、RuBP羧化酶含量及活性、叶片导度均有正效应，并有累加作用，而且对叶绿素含量缓降期和光合速率高值持续期也有正效应，因此带有Rht3基因的4B染色体具有促进光合作用的效应。

In order to obtain viable tetraploids, which remains a major challenge worldwide, research on spindle organization and chromosome behavior was carried out mainly in zhikong scallop, Chlamys farreri, a typical commercially important species which is being cultured in North China Sea. Immunofluorescent technique and laser scanning confocal microscopy has been developed for observation of both microtubule organization and chromosome segregation. Orcein squash method was also used for chromosome observation. A series of complicated configurations of the meiotic spindle and associated patterns of chromosome segregation, including tripolar and seperated bipolar segregation, were found in developing eggs following the inhibition of the first polar body.

为了攻克可存活四倍体人工培育技术的国际性研究难题，本研究选取了我国北方海区的典型经济贝类栉孔扇贝为主要研究对象，建立了一套免疫荧光染色和激光扫描共聚焦显微技术，结合使用染色体地衣红压片观察技术，对第一极体受抑制的受精卵的减数分裂纺锤体装配、染色体分离动态进行了研究，发现了一系列特殊的纺锤体装配及相应的染色体分离行为，包括三极分离、独立二极分离等分离类型，从亚细胞水平上阐明了四倍体形成的细胞学机理。

Additionally, analysis of G-banding patterns for macrochromosomes of them indicated that there was great difference between NO.1 and NO.2 chromosome, which can be explained by the pericentric inversions.

NO.l染色体，家鸡为m型，而鹌鹑为sm型；NO.4、NO.6、NO.8和Z染色体，家鸡分别为sm、sm、m、m型，而鹌鹑全为t型。G带分析结果显示，家鸡和鹌鹑的G带差异主要反映在NO.1、NO.2染色体上，这可能是由於臂间倒位所致。

Ninety-three patients with forty-two azoospermia and fifty-one severe oligozoospermia were recruited in present study. Y chromosome microdeletions were screened by detection of four locus SY84, SY134, SY255 and SPGY1 gene spaning the AZFa, AZFb and AZFc subregions of Y chromosome. The total incidence of Y microdeletions was 16%( 15/93 )in present study. Eight men in 42 patients with azoospermia had Y microdeletions, of whom 6 were AZFc deletion and 2 were AZFb deletion.

通过对93例男性不育（42例无精症和引例严重少精症）患者，Y染色体 SPGY基因、AZFa－SY84、AZFb－SY134和 AZFc－SY255位点缺失情况的研究，我们发现男性不育患者 Y染色体微缺失的发生率为 16％（ 5旧3人 42例无精子症患者中，有8例存在Y染色体微缺失，其中6例为AZF。

Secondly,proposed an new scheme that the double population genetic algorithm used the self-adaptable crossover operator and mutation operator according to the shortage of early convergence and stagnation in the traditional double population genetic algorithm based on unconvertible rate of crossover operator and mutation operator.

摘 要：介绍了图像关联规则的相关概念，描述了传统的双种群遗传算法的执行过程；针对采用固定染色体交叉概率和染色体变异概率容易出现早熟、收敛速度较慢等问题，设计出了能自适应调整的染色体交叉算子和变异算子。

Dinoflagellate have many traits different from prokaryotes and eukaryotes:the cells have nuclei, but the nuclear membrane is discontinuous; There are many chromosomes in the nuclei, but the chromosomes remain permanently condensed during cell cycle; The cristae of mitocondria is tubular, and the cells have no typical endoplasmic reticulum.

甲藻细胞虽有核膜，但双层核膜不连续；有多个形态结构完整的染色体，但染色体在整个生命周期中永远处于高度凝集状态，DNA纤维的折叠方式与典型真核生物中期染色体完全不同；线粒体的嵴为管状。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！