黄瓜根尖细胞中微管冷稳定性和微管蛋白与其抗寒性的关系

以不同抗寒性黄瓜品种为试材,研究了经不同时间低温处理后黄瓜根尖细胞中微管的动态变化及抗寒锻炼后微管蛋白的变化,结果表明黄瓜根尖细胞中不同部位的微管冷稳定性有差异,质膜下的周质微管具有最强的冷稳定性,抗寒品种黄瓜根尖细胞中微管冷稳定性明显高于不抗寒品种,同时抗寒锻炼后微管蛋白的含量有所增加.     

芽殖酵母Sik1蛋白在纺锤体定位中的功能

为了探究芽殖酵母蛋白Sik1在有丝分裂纺锤体定位中的功能,利用同源重组技术将SIK1的内源启动子替换成GAL1启动子,得到基因组位点过表达SIK1的菌株,同时使菌株表达GFP-Tub1,以便观察纺锤体;接着在12℃低温条件下培养细胞以促进双核细胞的产生,细胞经乙醇固定、DAPI染色后在荧光显微镜下观察细胞核分裂及纺锤体...     

微管和微丝在小鼠受精卵原核迁移中的作用

本文用微管、微丝解聚剂处理小鼠体内受精卵,发现雌雄原核的迁移均被抑制,说明雌雄原核的迁移是微管和微丝共同作用的结果。     

微管骨架在棉纤维细胞伸长中的作用

以陆地棉纤维为实验材料,研究了微管骨架在棉纤维细胞伸长阶段的功能.研究结果表明,在快速伸长期纤维细胞内,微管骨架以垂直于细胞伸长轴方向垂直排列,微纤丝的结构和分布与微管骨架保持一致,细胞壁表面平滑.经过微管阻断剂秋水仙素处理的纤维细胞内,微纤丝的结构和分布受到损坏,细胞壁表面出现颗粒状突起,纤维细胞的伸长也受到明显抑制.以上实验结果表明微管骨架在棉纤维细胞的伸长阶段具有重要的功能.     

玉米（Zea mays L．）盐逆境胁迫蛋白基因nac1的染色体原位杂交物理定位

报道了玉米低拷贝盐逆境胁迫蛋白基因ｎａｃ１生物素标记的染色体原位杂交结果．供试探针为这个基因的ｃＤＮＡ克隆,其长度仅为５５０ｂｐ．采用酶联免疫级联放大和ＤＡＢ检测系统检测,实验结果表明,杂交信号分布在第２染色体短臂和第１０染色体长臂,与着丝粒的百分距离分别为６７．５６±３．２９１和８０．９２±２．４１１,检出率分别为５．８１％和１０．３２％．并对植物单和低拷贝基因的染色体原位杂交技术与基因染色体原位杂交作图进行了讨论     

微管剪切蛋白Fidgetin在黑腹果蝇 神经发育过程中的功能初探

微管(microtubule,MT)是一种具有极性的细胞骨架.在微管动态变化过程中,有两类蛋白参与微管组装和解聚的动态调节.Fidgetin(Fign)的编码基因为CG3326,它是其中的去组装因子之一,参与微管剪切和末端解聚.本实验使用CRISPR/Cas9系统,构建fidgetin无功能突变体果蝇品系(fidgetin~(null)),观察fidgetin功能缺失对果蝇的神经发育的影响.结果表明fidgetin~(M14-2)会导致神经肌肉突触(neuromuscular junction,NMJ)的扣结数增多.通过观察fidgetin~(M14-2)的表型从而初步判断fidgetin基因对神经系统发育的影响,为fidgetin基因功能与致病机制的进一步研究提供基础.     

Ser10磷酸化的组蛋白H3和微管蛋白在小麦根尖细胞有丝分裂过程中的动态分布

利用间接免疫萎光标记技术研究Ser10磷酸化的组蛋白H3和微管蛋白在小麦根尖细胞中有丝分裂过程中的动态分布情况.结果显示在小麦根尖细胞有丝分裂过程中Ser10磷酸化的组蛋白H3的出现和消失与染色体的凝集和解凝集的过程存在时空上的相关性,在有丝分裂的过程中这种蛋白在着经线粒上的定位有有助于染色体向两极移动.研究结果还表明,在有丝分裂过程中,微管蛋白发生了重组,成束的垂直排列在赤道板的两侧,协助细胞有丝分裂过程的顺利完成.     

人酪蛋白激酶CK1γ1 cDNA的克隆、染色体定位和组织表达谱分析

从人胎脑cDNA文库中克隆到一种新的酪蛋白激酶的cDNA，全长1754dp，拟编码438个氨基酸残基，该蛋白预测的分子质量为50272u，等电点9．37，经同源分析，该基因在大鼠的CK1γ1蛋白有94％的相似性，为人1型酪蛋白激酶－γ1亚型基因，人CK1γ1基因同时与15号与17号染色体的基因组部分序列完全一致，但RH法却将基因定位于15q22区段的D15S159－D15S125 Marker之间，多组织Northern膜（MTN）杂交分析显示，人CK1γ1基因在肝，结肠，肾和骨骼肌特别在肝组织中有高表达。     

流感病毒NS1蛋白在复制中的作用研究

流感病毒NS1基因敲除毒株(delNS1毒株)的获得可以使我们建立更有效的生物学关系,主要表现在流感病毒繁殖周期和致病的过程中,流感病毒NS1蛋白和双链RNA活性蛋白激酶(PKR)之间的生物学关系.实验结果表明,缺少功能性的PKR可以使delNS1毒株在其他非允许宿主中繁殖,这表明流感病毒NS1蛋白的主要功能是对抗或阻止PKR调解抗病毒效应.     

Functions of spindle check-point and its relationship to chromosome instability

It is generally believed that the equal distribution of genetic materials to two daughter cells during mitosis is the key to cell health and development. During the dynamic process, spindle checkpoint plays a very important role in chromosome movements and final sister chromatid separation. The equal and precise segregation of chromosomes contributes to the genomic stability while aberrant separations result in chromosome instability that causes pathogenesis of certain diseases such as Down’s syndrome and cancers. Kinetochore and its regulatory proteins consist of the spindle checkpoint and determine the spatial and temporal orders of chromosome segregation.     

棕色田鼠第一对常染色体多态与染色体数目关系的研究

研究了棕色田鼠 (Microtusmandarinus)三种性别类型个体 (XY ,XX ,XO)的第一对常染色体多态与染色体数目之间关系 .发现第一对常染色体极不稳定 ,存在( 1 )M ,M (一对中部着丝点染色体 ) ;( 2 )M ,T ,T (一条中部着丝点染色体 ) ;( 3)T ,T ,T ,T(无中部着丝点染色体 )三种多态类型 .性别类型相同个体的染色体数目随第一对常染色体类型的不同发生有规律地变化 .认为罗伯逊断裂是引起棕色田鼠第一对常染色体多态及其染色体数目多态的主要原因     

Molecular dynamics simulation of site-directed mutagenesis of HIV-1 Tattrans-activator

The Cys-rich domain, core region and basic domain are highly conserved and very important to thetrans-activation activity of HIV-1 Tattrans-activator. The three-dimensional structures of 6 mutants of HIV-1 Tat protein were constructed with the methods of molecular dynamics simulation. The variations of the structures of the mutants have been analyzed and the factors that led to abolishment oftrans-activation activity have been discussed.     

Molecular dynamics simulations exploring drug resistance in HIV-1 proteases

Although HIV-1 subtype B still dominates the epidemic AIDS in developed countries, an increasing number of people in developing countries are suffering from an epidemic of non-subtype B viruses. What is worse, the efficacy of the combinational use of an-tiretroviral drugs is gradually compromised by the rapid development of drug resistance. To gain an insight into drug resistance, 10-ns MD simulations were simultaneously conducted on the complexes of the TL-3 inhibitor with 4 different proteases (B_wt, B_mut, F_wt and F_mut), among which the complex of the B_wt protease with the TL-3 inhibitor was treated as the control group. Detailed analyses of MD data indicated that the drug resistance of B_mut against TL-3 mainly derived from loss of an important hydrogen bond and that of F_wt was caused by the decrease of hydrophobic interactions in S1/S1’ pocket, while both of the two reasons mentioned above were the cause of the F_mut protease’s resistance. These results are in good agreement with the previous experiments, revealing a possible mechanism of drug resistance for the aforementioned protease subtypes against the TL-3 inhibitor. Additionally, another indication was obtained that the mutations of M36I, V82A and L90M may induce structural transforms so as to alter the inhibitor’s binding mode.     

具有种群动力学和非线性接触率的SIRS流行病模型

建立易感染类中具有 L ogistic种群增长和非线性接触率的 SIRS流行病模型 ;分析该模型的正不变集和平衡位置的存在性 ,研究了疾病消除平衡位置和地方病平衡位置的稳定性 ,最后给出一些数值模拟结果     

Genetic dissection of a thousand-grain weight quantitative trait locus on rice chromosome 1

Thousand-grain weight （TGWT） is an important factor affecting grain yield as well as grain quality in rice. A quantitative trait locus （QTL） qTGWTI-1 for TGWT was detected previously near DNA marker RG532 on the short arm of chromosome 1 in a recombinant inbred line （RIL） population derived from the indlca-indica rice cross Zhengshan97B （ZS97B）/Milyang46 （MY46）. In this study, two residual heterozygous lines （RHLs）, Chl and Ch2, derived from the ZS97B/MY46 RIL F7 population, were used to develop two Fe populations, RIL-1 and RIL-2. The genome of Chl and Ch2 contains a heterozygous region flanked by RM1--RM3746 and RM151--RM243 on the short arm of chromosome 1, respectively, but is homozygous in other regions. Two tightly linked QTLs, Gwl-1 and Gwl-2, with the same additive direction and similar effect on TGWT, were detected in the region of QTL qTGWTI-1 in population RIL-2. No QTL was detected in the population RIL-1. Four individual RHLs from the population RIL-2 carrying heterozygous segments flanked by RM151--RM10404, RM10381--RM243, RM10435--RM259 and RM10398--RM5359, respectively, were chosen to develop four F= populations. Ten maternal homozygotes and 10 paternal homozygotes were selected from each of the four F2 populations derived from the four RHLs. The four sets of near isogenic lines （NILs） were grown for phenotyping of TGWT and delimitation of Gwl-1 and Gw1-2. Results showed that Gwl-1 and Gw1-2 were located in the intervals RM10376--RM 10398 and RM10404--RM 1344 which cover 392.9 and 308.5 kb regions, respectively. The enhancing alleles were from ZS97B at both loci, and no significant interactions were detected. Genetic dissection of Gwl-1 and Gwl-2 has laid a foundation for their cloning and molecular breeding of grain yield and quality in rice.     

小型无人直升机纵向和横向动力学的鲁棒反推控制(英文)

研究了阵风情况下悬停飞行模式中的无人直升机的纵向与横向位置的稳定性问题.由于通用的线性模型成功地描述了大多数小型直升机的行为,其被用来设计控制器.基于控制Lyapunov方法,一种递归(反推)设计流程被用来设计纵向和横向动力学的鲁棒控制器.为了比较,我们基于线性二次调节器(LQR)准则设计了另一种控制器.仿真结果表明,所提出的反馈控制器能有效地减弱阵风的影响,在阵风下能够实现纵向和横向位置的快速、准确跟踪.     

5-硝基-1-氢-四唑衍生物热分解机理的从头算分子动力学模拟及密度泛函理论研究

应用从头算分子动力学模拟方法以及密度泛函理论对5－硝基－1－氢－四唑衍生物的热解机理进行了研究。报道了三条相关的反应途径，包括直接开环途径和质子转移途径，其中N1－N2键断裂直接开环的机理与文献报道一致。而涉及质子转移的反应途径则是一个新的发现。另一条关于C5－N4键断裂直接开环的途径由于能垒较高，因此发生几率较小。     

符号动力学,星花积及其他

混沌破坏了拉普拉斯的经典决定论1,从而改变了我们审视世界的观点,符号动力学则提供了这种观点的一种数学表达.