硬化性肌膜炎患者血清ACA的发现及对小鼠细胞着丝点的研究

首次在硬化性肌膜炎患者血清中发现有抗着丝点抗体(ACA),可使 Hep-2间期细胞核及 M 期细胞染色体着丝点显示分散的荧光斑点.用 ACA 血清对小鼠几种器官的冰冻切片或涂片进行免疫荧光研究,可见无论幼龄或老龄小鼠的肝、十二指肠、脑皮层细胞及老龄小鼠睾丸生精细胞均有明亮的荧光斑点.绒毛顶端细胞呈均匀性荧光.     

taxol对V79—8系细胞微核化机理的探讨

用多种方法探讨了 v_(79-8)系细胞在 taxol 作用下微核化的时期和机理.早熟染色体凝集(PCC)法发现此种 G_1 及 G_2 期缺陷的细胞株,在一定的生长条件下有相当数量的 G_1 和 G_2 细胞存在.taxol 作用后,首先是有丝分裂指数(I_m)的增加,然后随 I_m 的下降细胞微核化增加.秋水仙酰胺阻断的 M 期细胞,在释放的同时加入 taxol,细胞微核化速率增加迅速.微管的间接免疫荧光法显示,在 taxol 作用下,微管集合成不规则的束.微核化细胞可以继续合成 DNA.每个微核中含有可被抗着丝点抗体(ACA)血清荧光染色的着丝点.     

草地蚁的染色体核型

本文研究了草地蚁(Tetramorinm‘caespitum L．)的染色体核型，其2n=28，可配成14对，划分成4组，Ⅰ组(第1对)，Ⅱ组（第2～4对)，Ⅲ组(第5～11对)，Ⅳ组(第12～14对)．有5对中部着丝点染色休，2对亚中部着丝点染色体，7对亚端部着丝点染色体．     

染色体包装的特化部分

端粒、着丝点和次缢痕是染色体包装的特化部分，是染色体的形态学标志．本文重点介绍了它们的结构特点、组成和功能等方面的研究进展     

对减数分裂中染色体复制概念的剖析

由一条染色体变成两条染色体的过程称为染色体的复制．减数第一次分裂（简称减1）的间期只存在DNA的复制以及随后的染色单体的复制,不存在染色体的复制．减数第二次分裂（简称减2）的中期,随着一条染色体的着丝点发生分裂完成染色体的复制,由一条染色体变成两条染色体．     

香瓜属(Cucumis)植物染色体核型分析

用去壁低渗火焰干燥技术对香瓜属两个品种华兰氏和哈密瓜的染色体核型进行研究.结果表明:两种植物均具有24条染色体,中部着丝点的染色体9对,近中端着丝点的染色体3对,包括一对具随体的染色体.其核型公式均为:2n=24=18m+4sm+2sm(SAT),按照Stebbins的核型分类方法,细胞类型均为2A.通过本实验对华兰氏和哈密瓜染色体数目的确定,以及核型的分析,为今后对葫芦科尤其是香瓜属植物核型的分析研究提供了借鉴和依据.     

香瓜属（Ｃucumis）植物染体核型分析

用去壁低渗火焰干燥技术对香瓜属两个品种华兰氏和哈密瓜的染色体核型进行研究,结果表明：两种植物均具有２４条染色体,中部着丝点的染色体９对,近中端着丝点的染色体３对,包括对一对具随体的染色体,其核型公式均为：２n=24=18m 4sm 2sm(SAT),按照Ｓtebbins的核型分类方法,细胞类型均为２Ａ,通过本实验对华兰氏和哈密瓜染色体数目的确定,以及核型的分析,为今后对葫芦科尤其是香瓜属植物核型的分析研究提供了借鉴和依据。     

着丝点及其进化

着丝点和着丝粒不是同一细胞结构.近年来流行的着丝点结构模型是三层盘状结构,已知染色质丝环穿入着丝粒盘内,而且已发现三种着丝点蛋白质.新近的研究表明:印度赤麂的着丝粒是由中国赤麂的着丝粒单位线性融合进化而来.     

伪东方罂粟的染色体核型研究

本文研究了罂粟属的伪东方罂粟Ｐａｐａｖｅｒｐｓｅｕｄｏ－ｏｒｉｅｎｔａｌｅ根尖细胞的核型，结果证明该植物体细胞的染色体数目为２ｎ＝４２，ｘ＝７．具有６条中部着丝点染色体，３０条近中部着丝点染色体和６条近端部着丝点染色体，其核型公式为Ｋ（２ｎ）＝６ｘ＝４２＝６ｍ＋３０ｓｍ＋６ｓｔ。     

餐条的核型研究

以肾脏细胞制作染色体标本,研究了贵州境内的餐条的核型。根据对100个中期分裂相染色体的计数,结果表明:餐条中部着丝点染色体(m)8对;亚中部着丝点染色体(sm)13对;亚端部着丝点染色体(st)3对;无端部着丝点染色体(t).染色体臂数(NF)90,核型公式2n=48,16m+26sm+6st,NF=90.未发现异型染色体对。     

大蒜根尖细胞有丝分裂高峰期的研究

本文报道了一昼夜周期中大蒜根尖细胞在自然温度（１７～２１℃）和恒温（２５℃）条件下的有丝分裂高峰期和温度对大蒜根尖细胞有丝分裂高峰期的影响。     

葱属隶属地位的探讨

探讨了葱属的隶属地位，从形态特征，花粉特点和化学成分等方面对葱属及其相近属（石蒜属Lycoris,知母属Anemarrhena,百合属Lilium)分别进行了分析，最后选取23个性状，应用分支类中的最大同步法对其进行处理，结果表明，葱属和其它各属区别较大，不适于划归同一科，应别立葱科，将葱属隶属于其下。     

In vitro centromere and kinetochore assembly on defined chromatin templates

During cell division, chromosomes are segregated to nascent daughter cells by attaching to the microtubules of the mitotic spindle through the kinetochore. Kinetochores are assembled on a specialized chromatin domain called the centromere, which is characterized by the replacement of nucleosomal histone H3 with the histone H3 variant centromere protein A (CENP-A). CENP-A is essential for centromere and kinetochore formation in all eukaryotes but it is unknown how CENP-A chromatin directs centromere and kinetochore assembly. Here we generate synthetic CENP-A chromatin that recapitulates essential steps of centromere and kinetochore assembly in vitro. We show that reconstituted CENP-A chromatin when added to cell-free extracts is sufficient for the assembly of centromere and kinetochore proteins, microtubule binding and stabilization, and mitotic checkpoint function. Using chromatin assembled from histone H3/CENP-A chimaeras, we demonstrate that the conserved carboxy terminus of CENP-A is necessary and sufficient for centromere and kinetochore protein recruitment and function but that the CENP-A targeting domain--required for new CENP-A histone assembly--is not. These data show that two of the primary requirements for accurate chromosome segregation, the assembly of the kinetochore and the propagation of CENP-A chromatin, are specified by different elements in the CENP-A histone. Our unique cell-free system enables complete control and manipulation of the chromatin substrate and thus presents a powerful tool to study centromere and kinetochore assembly.     

Effects of sense and antisense centromere/kinetochore complex protein-B （CENP-B） in cell cycle regulation

This paper investigates the effects of sense and antisense centromere/kinetochore complex protein-B （CENP-B） in cell cycle regulation. Full-length cenpb cDNA was subcloned into pBI-EGFP eukaryotic expression vector in both sense and antisense orientation. HeLa-Tet-Off cells were transfected with sense or antisense cenpb vectors. Sense transfection of HeLa-Tet-Off cells resulted in the formation of a large centromere/kinetochore complex, and apoptosis of cells following several times of cell division. A stable antisense cenpb transfected cell line, named HACPB, was ob- tained. The centromere/kinetochore complex of HACPB cells became smaller than control HeLa-Tet-Off cells and scattered, and the expression of CENP-B was down-regulated. In addition, delayed cell cycle progression, inhibited malignant phenotype, restrained ability of tumor formation in nude mice, and delayed entry from G2fM phase into next G1 phase were observed in HACPB cells. Furthermore, the expression of cyclin-dependent kinases （CDKs）, cyclins, and CDK inhibitors （CKIs） were modulated during different phases of the cell cycle. CENP-B is an essential protein for the maintenance of the structure and function of centromere/kinetochore complex, and plays important roles in cell cycle regulation.     

Two mitotic kinesins cooperate to drive sister chromatid separation during anaphase

During anaphase identical sister chromatids separate and move towards opposite poles of the mitotic spindle. In the spindle, kinetochore microtubules have their plus ends embedded in the kinetochore and their minus ends at the spindle pole. Two models have been proposed to account for the movement of chromatids during anaphase. In the 'Pac-Man' model, kinetochores induce the depolymerization of kinetochore microtubules at their plus ends, which allows chromatids to move towards the pole by 'chewing up' microtubule tracks. In the 'poleward flux' model, kinetochores anchor kinetochore microtubules and chromatids are pulled towards the poles through the depolymerization of kinetochore microtubules at the minus ends. Here, we show that two functionally distinct microtubule-destabilizing KinI kinesin enzymes (so named because they possess a kinesin-like ATPase domain positioned internally within the polypeptide) are responsible for normal chromatid-to-pole motion in Drosophila. One of them, KLP59C, is required to depolymerize kinetochore microtubules at their kinetochore-associated plus ends, thereby contributing to chromatid motility through a Pac-Man-based mechanism. The other, KLP10A, is required to depolymerize microtubules at their pole-associated minus ends, thereby moving chromatids by means of poleward flux.     

Molecular mechanisms of kinetochore capture by spindle microtubules

For high-fidelity chromosome segregation, kinetochores must be properly captured by spindle microtubules, but the mechanisms underlying initial kinetochore capture have remained elusive. Here we visualized individual kinetochore-microtubule interactions in Saccharomyces cerevisiae by regulating the activity of a centromere. Kinetochores are captured by the side of microtubules extending from spindle poles, and are subsequently transported poleward along them. The microtubule extension from spindle poles requires microtubule plus-end-tracking proteins and the Ran GDP/GTP exchange factor. Distinct kinetochore components are used for kinetochore capture by microtubules and for ensuring subsequent sister kinetochore bi-orientation on the spindle. Kar3, a kinesin-14 family member, is one of the regulators that promote transport of captured kinetochores along microtubules. During such transport, kinetochores ensure that they do not slide off their associated microtubules by facilitating the conversion of microtubule dynamics from shrinkage to growth at the plus ends. This conversion is promoted by the transport of Stu2 from the captured kinetochores to the plus ends of microtubules.     

内蒙古葱属植物的地理分布

分析讨论了内蒙古地区葱属植物的地理分布,结果表明,葱属主要分布于内蒙古高原中部、东部及周缘山地,按植物区系分区,欧亚草原区种类最多,呼锡高原州分布最为集中,对内蒙古葱属分类系统进行了修订。     

Progress and perspective of the kinetochore-associated motor proteins

The kinetochore is structurally composed of four layers,We know that three microtubule-based motor protcins such as CENP-E,dynein,and MCAK are located at the outmost region of the kinctochore,Experimentation of these motot functions betters our understanding of mitotic regulation,and chromaosme movements in particular,With real-time studies of chromosome movements in live cells,we hope to illustrate the molecular mechanisms under lying mitotic regulation.     

大蒜根尖分生组织核仁纤维中心形态结构扫描电镜研究

报道了大蒜（Allium Sativum L.)根尖生分组织细胞核仁纤维中心（FC．）的亚微结构，为在扫描电镜下研究植物细胞核及核仁的形态结构提供参考资料。