性细胞遗传的

Keywords potato virus Y, coat protein gene, transgenic tobacco, RNA-mediated,,,,resistance, genetic analysis, cytopathology

马铃薯Y病毒；细胞病理学； CP基因；转基因烟草； RNA介导的抗病性；遗传分析

In recent years, by using sex chromosome or cell surface antigen as a marker, the characteristics of proliferation and differentiation of spleen colony-forming cells have been studied systematically.

近年来，许多学者采用天然的性染色体或是细胞的特异表面标志作为细胞遗传标志深入、系统地研究了脾结节生成细胞（spleen colony-forming cell，CFC-S）的增殖与分化性能。

Sickle cell disease, also called sickle cell anemia, is a genetic condition that deforms red blood cells.

镰状细胞病也叫做镰刀性细胞贫血病，是红细胞残缺的一种基因遗传类疾病。

Gimelbrant et al. determined the proportion of human genes that can be expressed monoallelically, in patterns that are epigenetically stable (for example, chemical modifications of DNA, such as cytosine methylation, that do not alter the sequence but are heritable within cell populations).

Gimelbrant等确定部分人类基因，能够单等位基因性表达，在表达模式上，后生同类物稳定（例如，化学修饰的DNA ，如胞嘧啶甲基化，不改变序列，但内细胞群是可遗传的）。

2N gametes are the result of meiotic mutation during micro- and mega-sporogenesis that bear the sporophytic rather than the gametophytic chromosome number. This paper reviewed the genetic markers including the morphologic, cytological, isozymes and DNA markers, which have been employed in the generation, inheritance, heterozygosity and marker-assisted breeding of 2n gametes based on the frequency of large pollen grains, cytological analyses, unexpected occurrence of polyploidy progeny and the associations between parents and progenies.

文章综述了植物2n配子发生及其遗传标记研究现状，论述涉及有关形态学标记、细胞学标记、同工酶标记乃至DNA标记等遗传标记在2n配子研究中的应用，指出通过花粉形态观察、大小孢子母细胞减数分裂行为观察、杂种后代倍性鉴定以及亲子分子标记相关分析等，对2n配子发生、2n配子遗传类型与杂合性以及2n配子在育种实践中的有效性等进行研究。

Micronucleus test results exhibited that significant differences in micronuclear rates were determined between 0.4 mL bone cement and 0.4 mL microsphere-coated bone cement groups and negative control group, but no significant difference was detected among other groups. This revealed that this microsphere-coated bone cement leaching liquor did not show significant cell heredity toxic effects. Nevertheless, microsphere-coated bone cement in the high concentration and high dosage groups exhibited low toxic effects, mainly showing increased hemolysis rate and micronuclear rate. Thus, it was necessary to control the dosage and concentration of microsphere-coated bone cement.

微核实验结果显示除0.4 mL骨水泥组和0.4 mL微球骨水泥组的微核率与阴性对照组差异有显著性意义，其余各组差异无显著性意义，说明该微球骨水泥的浸提液无明显细胞遗传毒性作用，但是高浓度和高剂量组的微球骨水泥仍有较低的毒性作用，主要表现为溶血率和微核率的提高，因此在应用时要适当控制微球骨水泥的剂量和浓度。

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。

Apoptotic cells have immunogenicity,and may be the major source of autoantigens in lupus BXSB mice.Lupus genetic factors and Yaa gene can potentiate the immunogenicity of apoptotic cells or accelerate their inducing the lupus nephritis.

凋亡细胞具有免疫原性，它可能是狼疮性BXSB小鼠体内自身抗原的主要来源；狼疮性遗传因素和Yaa基因能促进凋亡细胞的免疫原性和增强凋亡细胞的致肾炎作用。

Apoptotic cells have immunogenicity,and may be the major source of autoantigens in lupus BXSB mice.Lupus genetic factors and Yaa gene can potentiate the immunogenicity of apoptotic cells or accelerate their inducing the lupus nephritis. Apoptosis; Mice,BXSB; Lupus erythematosus,systemic

凋亡细胞常识具有免疫病毒原性，它可能流产是狼疮性BXSB小鼠体内自身抗原的主要来源；狼疮性遗传因素和Yaa基因能促进凋亡细胞常识的免疫病毒原性和增强凋亡细胞常识的致肾炎作用。

Some stimulators, including viruses, tumor cells and hot shock, could promote the expression of NKG2 receptors and their ligands via activating certain transcription factors which are capable of up-regulating NKG2 promoters' activity. Meanwhile, epigenetic mechanisms including DNA methylation and histone posttranslational modifications are also critical to expression of NKG2 receptors and their ligands and may control the clonally distribution of some NK cell receptors.

病毒、肿瘤和热休克等刺激可以通过激活相应的转录调节因子，提高启动子活性而上调NKG2家族受体及其配体的表达，而启动子区DNA的甲基化状态、组蛋白的乙酰化和甲基化等表观遗传调控，在NK细胞受体及其配体的表达方面亦起重要作用，并决定NK细胞受体的克隆性分布。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。