人体肝癌细胞BEL-7402系染色体G分带方法的探讨

染色体分带技术的建立是七十年代以来细胞遗传学研究手段的一项新突破。它可运用于鉴别不同组号的染色体,而且可辨明精细的染色体结构变化,因而在生物学和医学方面都得到了广泛的应用,是物种的系统发生、遗传疾病以及肿瘤等研究工作的重要手段之一。染色体分带方法种类繁多,应用最普遍的是G带,即Giemsa分带,尤其是胰旦白酶——Giemsa分带法。由于方法简便迅速,带纹细致,制片可以长期保存,故为众多的实验室所乐用。可是,经过胰酶处理的染色体容易肿胀。为了取得优良的、能供分析的带纹样式,许多实验室在Seabright氏首先建立的方法基础上进行了改良,方法不下几十种。本文就五种主要的胰酶—G带法以及高分辨率G带法处理BEL—7402细胞所获得的结果进行比较。     

柑桔种质离体保存研究

以锦橙和红桔的腋芽分化的丛芽进行中长期离体保存试验．单因素试验结果表明，封口膜是最理想的封口材料；正交试验结果表明，锦橙和红桔保存的最佳条件分别为：ＭＳ＋２％甘露醇和ＭＳ＋ＢＡ２ｍｇ／Ｌ＋ＩＡＡ０１ｍｇ／Ｌ＋２％甘露醇，均在１５℃，５００ｌｘ光照下培养．上述条件下，供试材料继代间隔周期可延长至１年，从而达到了种质离体慢生长（Ｓｌｏｗｇｒｏｗｔｈ）保存的目的．保存１年后的丛芽嫁接苗的ＰＯＸ同工酶分析和染色体计数证明其遗传性是稳定的．     

不同品系黑腹果蝇细胞系的建立（Ⅱ）——黑条体突变型（BSR）细胞？…

为了广泛选择外源真核基因高频扩增及高效表达的载体和黑体系统，利用改良的Ｍ３（ＢＦ）培养基从黑腹果蝇黑条体的胚胎中建立了一株细胞系命名为ＢＳＲ－９８０４，原代培养４０ｄ形成单层细胞，以１：２分种率７ｄ传代一次，连续传代４０代次，细胞倍增时间为１８ｈ，细胞系以２倍染色体为主，未发现结构异常的染色体，２％胎牛血清为维持细胞生存的最小需要量，细胞系可在４℃普通冰箱中保存复苏。     

转基因鸡的染色体核型分析

为了研究外源基因p53对鸡自身染色体核型是否有影响,以含有外源基因p53的转基因公鸡为试验组,以同种非转基因公鸡作为对照组,通过外周血淋巴细胞培养法和骨髓法,制备了鸡染色体标本片。在油镜下随机选择50个染色体分散良好的细胞,测量染色体的条数、相对长度、臂比值和着丝粒指数,确定并比较转基因鸡和非转基因鸡的染色体形态。研究结果表明:试验组和对照组公鸡的染色体条数均符合2n=78条,均包括10对大染色体和29对微小染色体,且微小染色体基本为端着丝粒染色体。两组的染色体核型均由38对常染色体和1对同配型性染色体ZZ组成,1号染色体、2号染色体和1对性染色体(ZZ)均为中央着丝粒(m)染色体,3号染色体均为端着丝粒(t)染色体,4号染色体均为亚中央着丝粒(sm)染色体,6~10号染色体均为端着丝粒(t)染色体。     

小麦体细胞再生株中等臂染色体构型

对10株具有等臂染色体的体细胞再生株进行染色体构型分析,共有4种构型; (1)等臂染色体2n=42,(2)双等臂染色体2n=42,(3)等臂染色体和易位染色体2n=42,(4)双等臂染色体和易位染色体2n=42。 在组织培养过程中,由于存在着普遍的染色体断裂和重接现象。而再生株中的等臂染色体是当代产生,因此推测等臂染色体可能是由染色体发生断裂,形成端部着丝点染色体,经复制后,分裂时趋向一极形成等臂染色体。     

基因保存与人的“重塑”

您愿意花上5美元把自己的基因保存起来吗?因为未来的人类可以为这些基因"重塑"你——更精确地说,一个有你的染色体并和你相像的人,这人会有一些跟你相似的生理特征。在美国西雅图有一个名为Third Millennium Research的公司提供一项特殊服务——保存基因。该公司会根据客户的的要求,向客户免费提供一个"无痛、安全收     

长序狼尾草的核型分析

本文对长序狼尾草的染色体组型作了观察分析,确定其染色体数目为2n=6x=54。按Lima-De-Faria的分级标准,其染色体可分为中等大小染色体和小染色体(N0.1—5)和小染色体(N0.6—27);按郭幸荣等提出的分类方法来进行分析,其染色体亦可分为中短染色体M_1(N0.1—21)和短染色体S(N0.22—27)。因此,长序狼尾草的染色体属于小型染色体类。另外,在N0.1和N0.6染色体一臂上分别存在有一对随体     

基于基因表达式编程的终端区飞机优化排序模型设计

终端区飞机排序是空中交通流量管制部门关注的热点问题,通过研究基因表达式编程在终端区飞机排序中的应用,设计了可回溯基因表达式编程的优化排序算法。该算法在染色体进化时使用改进的操作算子——最大区间约束倒置操作符,解决进化中出现的无效解和无用解问题;在种群繁衍时采用了回溯进化技术,为较优种群更好地保存,对回溯栈的操作改进为不...     

中国羚牛的染色体研究

本项研究是用一头雄性和一头雌性羚牛的血液经外用血培养,并对其染色体组型和G带进行分析。结果表明这雌雄两头羚牛的二倍染色体数皆为2n=52,其常染色体中有4对近中着丝点染色体和21对端着丝点染色体;在性染色体中,x染色体为端着丝点染色体,y染色体为近中着丝点染色体。并对G带带纹进行逐条分析。     

人hIGF-1在Pichia pastoris酵母中的分泌表达及表达产物的鉴定

根据人IGF-l(Human Insulin-like Growth Factor-1，hIGF-1)的天然基因序列，在尽量保存原基因序列的基础上，将一些密码子换成Richia pastoris酵母的偏爱密码子，人工合成hIGF-1双链DNA.将此合成基因整合人X-33酵母的染色体上，用Zeocin+平板筛选得到重组菌株.以胞外分泌的方式表达了hIGF-1蛋白，表达产物经聚丙烯酰胺凝胶电泳和western-blot分析，得到该表达产物的相对分子质量约为7200.     

蝗虫染色体C-带核型研究进展(昆虫纲:直翅目)

对染色体C-带核型分析及其技术和方法在蝗总科的应用进行了综述,并对我国已有染色体C-带核型分析的蝗虫种类进行了统计.     

Identification of embryonic chromosomal abnormality using FISH-based preimplantation genetic diagnosis

Objective: Embryonic chromosomal abnormality is one of the main reasons for in vitro fertilization (IVF) failure. This study aimed at evaluating the value of Fluorescence in-situ Hybridization (FISH)-based Preimplantation Genetic Diagnosis (PGD) in screening for embryonic chromosomal abnormality to increase the successful rate of IVF. Method: Ten couples, four with high risk of chromosomal abnormality and six infertile couples, underwent FISH-based PGD during IVF procedure. At day 3, one or two blastomeres were aspirated from each embryo. Biopsied blastomeres were examined using FISH analysis to screen out embryos with chromosomal abnormalities. At day 4, embryos without detectable chromosomal abnormality were transferred to the mother bodies as in regular IVF. Results: Among 54 embryos screened using FISH-based PGD, 30 embryos were detected to have chromosomal abnormalities. The 24 healthy embryos were implanted, resulting in four clinical pregnancies, two of which led to successful normal birth of two healthy babies; one to ongoing pregnancy during the writing of this article; and one to ectopic pregnancy. Conclusion: FISH-based PGD is an effective method for detecting embryonic chromosomal abnormality, which is one of the common causes of spontaneous miscarriages and chromosomally unbalanced offsprings.     

Introduction of homologous DNA sequences into mammalian cells induces mutations in the cognate gene

Injection of homologous DNA sequences into nuclei of cultured mammalian cells induces mutations in the cognate chromosomal gene. It appears that these mutations result from incorrect repair of a heteroduplex formed between the introduced and the chromosomal sequence. This phenomenon is termed 'heteroduplex induced mutagenesis'. The high frequency of these events suggests that this method may prove useful for introducing mutations into specific mammalian genes.     

染色体技术在遗传性疾病临床诊断中的应用

探讨了染色体技术对临床诊断某些疾病的应用价值 .应用常规外周血淋巴细胞染色体标本制备 ,G显带、C显带技术 ,脆性X染色体分析 .结果从 3 89例患者中检出异常核型 46例 ,检出率为 11.83 % .其中罗伯逊易位携带者 6例 ,平衡易位携带者10例 ,倒位携带者 4例 ,性染色体异常者 14例 ,先天愚型及发育异常者 12例 .结果表明 ,染色体技术是某些遗传性疾病临床诊断必不可少的手段 ,异常染色体的检出对患者的治疗、预后及优生、优育、优教都有重要指导意义 .     

Chromosome microdissection by laser microbeam, chromosomal fragment isolation and amplificationin vitro in barley (Hordeum vulgare L.)

A method for microdissection, isolation and amplification of plant chromosomal fragments using laser microbeam and a glass microneedle was established. Firstly, 7H chromosome of barley (Hordeum vulgare L.) was dissected by Nd: YAG laserbeam with suitable parameters and the fragment comprising a satellite was isolated with a glass microneedle which was fixed on a micromanipulator. Then, the chromosomal fragment DNA was amplified by LA_PCR (linker adaptor PCR) for two rounds. The size of the DNA fragments of PCR products varied from 500-3 000 bp and the PCR products originated from the genome of barley were verified by Southern hybridization. Compared with previous reports, there are some advantages in this research. The performance is easier, the dissection is more precise and the cost is low. It also permits efficient amplification with only one single chromosome fragment. Laser microbeam_glass microneedle method may be useful in the microdissection of special chromosome regions, especially in plants with middle or small chromosomes.     

88例疑有染色体异常者细胞遗传学分析

本文对８８例疑有染色体异常者进行了检查，发现染色体异常者７例，检出率为７．９５％。其中染色体数目异常者５例，染色体结构异常者２例。此外，尚有女性假半阴阳者和染色体变异者各１例。笔者对各种异常核型进行了分析。     

蚕豆根尖微核试验在环境致突变物检测中的应用

蚕豆根尖微核试验是一种以染色体损伤为测试终点的植物微核检测方法.简述了该方法的建立和基本原理,综述了其在水体的致突变性、空气污染物的致突变性、农药的致突变性和其他环境致突变物检测中的应用.     

大蒜根尖细胞在观察有丝分裂中的应用

介绍大蒜根尖细胞有丝分裂标本的制备方法。该方法适用于课堂教学中对正常植物组织有丝分裂过程的观察。由于细胞中的微核、染色体畸变极易识别,也可用于检测环境诱变剂。     

Chromosomal evolution in Saccharomyces

The chromosomal speciation model invokes chromosomal rearrangements as the primary cause of reproductive isolation. In a heterozygous carrier, chromosomes bearing reciprocal translocations mis-segregate at meiosis, resulting in reduced fertility or complete sterility. Thus, chromosomal rearrangements act as a post-zygotic isolating mechanism. Reproductive isolation in yeast is due to post-zygotic barriers, as many species mate successfully but the hybrids are sterile. Reciprocal translocations are thought to be the main form of large-scale rearrangement since the hypothesized duplication of the whole yeast genome 10(8) years ago. To test the chromosomal speciation model in yeast, we have characterized chromosomal translocations among the genomes of six closely related species in the Saccharomyces 'sensu stricto' complex. Here we show that rearrangements have occurred between closely related species, whereas more distant ones have colinear genomes. Thus, chromosomal rearrangements are not a prerequisite for speciation in yeast and the rate of formation of translocations is not constant. These rearrangements appear to result from ectopic recombination between Ty elements or other repeated sequences.