查询词典 mutation

Results The human pancreatic cancer cell line Patu 8988 had point mutation at codon 12 and the mutation style was GGT→GTT. The result of PCR-SSP was completely in accord with that of sequence analysis.

结果 PCR-SSP法检测人胰腺癌细胞株Patu 8988存在K-ras基因点突变，突变方式为GGT→GTT，其结果与基因序列测定完全相符。

Methods Three kinds of special sequence primers for polymerase chain reaction with regard to the mutation styles (CGT、GTT、GAT) at codon 12 of K-ras were used to study the human pancreatic cancer cell line Patu 8988.The amplification products were studied with 12% polyacrylamine gel eletrophoresis to detect the style of point mutation.

针对K-ras基因第12位密码子点突变方式(CGT、GTT、GAT)设计顺序特异性引物，对人胰腺癌细胞株Patu 8988进行聚合酶链反应，扩增产物经12%非变性聚丙烯酰胺凝胶电泳后判断该细胞株有无K-ras基因点突变及其突变方式。

Chapter five looks at the mutation in language stream with contemporary philologic theories. The characteristics of mutation in changshan dialect are supposed to be show by tone changing , light syllable, r-suffixation, z-suffixation,etc.我每is possibly the r-suffixation of women我们;Some final varied pattern of suffix子is actually r-suffixation;Changshan dialect"s light syllable lies in every level of language and it has multifold forms; There is rich tone change of verbs which can present certain grammatical meanings in Changshan"s dialect.

第五章动态的描写了长山方言中的语流音变，利用当代语音、语法、语义理论从轻声变调、语法变调、小称变韵、子变韵等几个方面考察长山方言语流音变的特点，认为&我每&有可能是&我们&的小称形式；以闻喜方言为代表的&子变韵&并不是&子&音转变而来，而是&儿化&的一种形式；长山方言的轻声变调存在于词汇、短语、句子等多个语言层面，有三种表现形式；轻声助词&了&、&着&、&到&省略后，会引起前面动词的语法变调，等等。

MATERIALS AND METHODS: Arg to Ser mutation was introduced into the 249 position of the p53 gene by knock-in method. These ES cells with this mutation were selected according to the homologues-recombination with PCR and Southern blot. The positive ES cells without a selection marker were injected into blastocysts recovered from Hprt(superscript -/-) mice, which were derived from Hprt-deficient ES cells. The injected blastocysts then were implanted into pseudopregnant females.

材料与方法：利用基因打靶技术在小鼠胚胎干细胞p53基因249编码子中引入点突变，使编码子249由精氨酸变成丝氨酸，然后将含突变的ES细胞显微注射到Hprt小鼠囊胚中，将注射过的囊胚植入假孕的雌性小鼠子宫，到第14d取小鼠胚胎纤维母细胞，用含HAT的培养液筛选出从ES细胞分化而成的鼠EF细胞，经测序证实细胞含有由249Arg到Ser的突变。

Missense mutation of Tyr486Asp in Exon 5 of UGT1A1 gene is the pathogenic factor of the CNⅡ case in the family and recessively inherited. The mutation has no influence on the response elements of phenibarbital in the promoter region.

Tyr486Asp突变是本例CN-Ⅱ家系的致病性基因，该突变不影响UGT1A1基因启动子区苯巴比妥酸的应答元件，其遗传规律符合常染色体隐性遗传。

To investigate the gene mutation of clinical and neuroelectrophysiological characteristics in Machado-Joseph disease. The gene mutation was detected in 45 patients diagnosed as spinocerebellar ataxia and 30 "healthy relatives". Brain stem evoked potentials, visual evoked potentials and motor conduction velocity and sensory conduction velocity were performed on MJD.

为了解Machado-Joseph病基因突变及临床的神经电生理特点，对16个诊断为遗传性小脑性共济失调家系的45例病人及30例家系的&正常&人作MJD基因突变分析，检出MJD基因的病人行肢体运动及感觉神经传导速度、脑干诱发电位，视觉诱发电位的检查。

A set of spectific primers was syn thesized according to HBV DNA sequence of Chinese strain, the whole X region was amplified by PCR method from the serum of 9 patients with chronic HBV infection , and then the PCR products were subcloned into pGEM Teasy vectors. Clones were randomly selected to be sequenced. Comparison of the cloned sequence was made to find the difference. After being compared, each sequence of selected clones is o f difference. The point mutation scattered through X region. Deletion mutations were detected in 19 clones of 37(51.4%), which caused different carboxyl endings of X protein. There is a hot region (after 123 aa code) where deletion mutation frequently happens.

以中国株HBV基因序列为依据，设计特异性多聚酶链反应引物，自9例慢性HBV感染患者血清中扩增HBV X基因，克隆入pGEM Teasy质粒，随机挑选克隆进行D NA测序以确定病毒的变异程度。37例测序结果提示来源于不同患者HBV X基因序列高度保守，但每个序列均不一致。X区除了存在广泛的碱基点替换突变外，序列的缺失突变占测序克隆总数的51.4％（19／37）；氨基酸缺失及移框突变多发生于123位氨基酸残基之后，可导致X蛋白多种羧基端形式。

Reactive oxygen species causing DNA oxidative damage comes from two kinds of ways:one is from cellular normal physiological metabolism;the other is from outer environment.Redox-sensitive green fluorescent protein was expressed in Saccharomyces cerevisiae.Recombinant cells were evaluated in monitoring the changes in the redox state of living cells when challenged with toxicologically relevant metal ions NaAsO_2 or Pb(NO_3)_2 by measuring emission intensity at 510 nm with a Hitachi F6500 fluorescence spectrophotometer,roGFP expressed in yeast responded not only to typical membrane-permeant oxidants H_2O_2 and reductants DTT,but also to toxicological metal ion-induced intracellular redox changes in a dose-dependent manner.Moreover,exposure of yeast cells to NaAsO_2 or Pb(NO_3)_2 at concentrations that induced redox changes reported by roGFP caused up to 2～3 fold increases in DNA mutation frequency.This mutagenic effect was largely caused by oxidative stress since blocking the production of hydryl radicals with thiourea significantly reduced the mutation rate as well as delayed the cell death.

本文将对氧化还原状态变化敏感的绿色荧光蛋白roGFP1-R12，在酵母细胞中实现了多拷贝强表达；荧光扫描经强氧化剂H_2O_2和还原剂DTT以及环境中重金属NaAsO_2或Pb(NO_3)_2处理后的酵母细胞悬液，测定510 nm处的荧光发射强度结果显示，表达的绿色荧光蛋白对氧化还原水平敏感，且在510 nm处的荧光强度与一定的重金属浓度呈正相关，即roGFP1-R12在510nm处的荧光发射值随重金属浓度的增高而增强，从而说明重金属对细胞的毒性在一定程度上很可能是通过破坏细胞内的氧化还原平衡发生作用；同时通过该绿色荧光蛋白对胞内氧化还原状态变化的响应情况可以来实时检测环境中的重金属；遗传学的点突变频率及致死率实验数据表明，重金属能导致菌体的点突变频率和致死率升高，且活性氧的清除剂巯基脲能明显降低这种点突变和致死率，说明由重金属引发的这种点突变和致死效应在很大程度上是依赖于重金属对细胞诱导产生的氧化胁迫。

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。

Results Mobiligy shifts of SSCP in exon 5 of presenilin-1 was detected in 4 cases with Alzheimer,s disease. Two missense mutation were found in the patients by DNA sequence analyse, one mutation was Leu 130 Met and the other was Vall 57 Leu.Another 11 patients showed one single strend shifted rapidly. But none mobility shifts of SSCP were found in patients with vascular dementia and normal controls. Conclusions It is shown that mutations in exon 5 of presenilin-1 also exist in the patients with sporadic Alzhemer?

结果 发现4名SAD患者的PCR产物SSCP分析发生泳动异常，DNA序列分析发现：这4名SAD患者的130号密码子发生了CTG→ATG错义突变(388位点发生C→A突变)，使编码的氨基酸由亮氨酸变为蛋氨酸(Leu 130 Met)；157号密码子发生了GTG→CTG错义突变(469位点发生G→C突变)，使编码的氨基酸由缬氨酸变为亮氨酸(Val 157 Leu)，另有11名患者SSCP表现为一条单链增快，其性质待定。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。