甲醛致大鼠鼻腔癌与K-ras癌基因活化相关

为探讨甲醛致大鼠鼻腔癌的分子机制,对甲醛诱发的大鼠鼻腔癌细胞系FAT7中的转化序列进行检测.采用的实验方法,包括肿瘤细胞DNA与选择标志基因(neo)共转染、裸鼠成瘤性分析、Southern杂交、聚合酶链反应(PCR)和序列分析等.结果发现:在第二轮裸鼠肿瘤DNA中含有大鼠源性的K-ras基因序列,而无大鼠源性的H-ras、N-ras和p53基因序列.这表明甲醛诱发的大鼠鼻腔癌细胞系FAT7中所含的转化序列与H-ras、N-ras及p53基因无关,K-ras癌基因的活化可能参与甲醛致大鼠鼻腔癌.     

鹅细小病毒主要免疫原性蛋白基因的克隆与序列分析

利用PCR技术,从纯化鹅细小病毒SYG99-5毒株鹅胚尿囊液中扩增出病毒主要免疫原性蛋白基因.将该PCR扩增片段克隆入pGEMR-T质粒载体的HincⅡ和SacⅠ位点之间,酶切分析筛选并进一步通过Southern杂交验证后,获得含1.6kb基因片段的重组质粒GpG3.序列测定结果表明,该片段与国外已报道的GPV B株苷酸序列有96%的同源性,氨基酸序列有97%的同源性.     

雄牛特异的SRY同源序列的扩增和分析

利用人、兔、鼠SRY序列设计引物,应用PCR扩增牛的SRY序列,获得200bp的雄牛特异的扩增片段。克隆该扩增片段,获得重组质粒pCH21,进行序列分析,并与人、兔和鼠SRY的对应区域比较,具有高度同源性。用pCH21 DNA作探针与牛的基因组DNA酶切图谱杂交,显示了雄牛特异的I．7kb的杂交带。分析200bp的PCR扩增片段是牛的SRY基因片段。用同一对引物扩增人和山羊的DNA样品,也获得雄性特异的200bp的扩增片段。     

结球甘蓝抗TuMV相关基因的克隆

以结球甘蓝高抗TuMV自交不亲和系84075为材料,构建了cDNA文库。根据抗病基因保守序列（NBS－LRR）设计一对简并引物,以84075的基因组DNA和cDNA为模板,进行PCR扩增,分别扩增出一条513bp片段,扩增片段进行克隆测序。选取两个与抗病基因同源性较高的克隆片段作探针（命名Borl,Bor2）,对构建的cDNA文库进行筛选,得到一个阳性克隆（命名TuR2）,测序及序列分析表明,该基因总长为762bp,编码226个氨基酸、包含681bp的开放阅读框。与已克隆的抗病基因有不同程度的同源性。利用TuR2作探针,进行了Southern杂交、Northern杂交以及抗病性的共分离检测分析。结果表明,TuR2可能吧单拷贝形式存在,其表达是组成成型的,且无组织特异性;初步确定是一个与结球甘蓝抗TuMV相关的基因。     

鼻咽癌上皮细胞株HNE1差异表达基因的分离与鉴定

为了分离鼻咽癌差异表达基因 ,应用抑制性扣除杂交技术 ,在正向抑制性扣除杂交中 ,以鼻咽癌上皮细胞株HNE1cDNA作为检测子 ,以人胚鼻咽上皮细胞cDNA作为驱赶子 ;在反向抑制性扣除杂交中 ,以人胚鼻咽上皮细胞cDNA作为检测子 ,以鼻咽癌上皮细胞株HNE1cDNA作为驱赶子 ,分别通过抑制性扣除杂交 ,构建了鼻咽癌上皮细胞株HNE1表达下调和表达上调的两个扣除cDNA文库 .从鼻咽癌相关的扣除cDNA文库中随机挑取 1 2 0 0个克隆 ,采用菌落PCR扩增其插入cDNA片段 ,自动点膜制备成cDNA微阵列膜 ,分别用鼻咽癌上皮细胞株HNE1、人胚鼻咽上皮mRNA经逆转录标记cDNA探针 ,分别与cDNA微阵列膜杂交 ,通过杂交信号的自动扫描分析 ,对杂交信号存在 5倍差异的克隆进行测序 ,获得了 1 0个鼻咽癌差异表达基因的cDNA片段 ,其中 3个为新基因序列 ,其GenBank登录号为 :AF5 1 0 1 88、AF5 1 0 1 89和AF5 1 0 1 90 ,7个代表已知基因序列 .采用RT PCR证实S1 0 0A8,CK1 9和RBP1基因在人胚鼻咽上皮中高表达而在鼻咽癌细胞株HNE1中低表达 .这些结果显示上述基因可能是鼻咽癌发生的重要因素     

人肺癌基因组DNA对NIH／3T3细胞的转化作用

从未用过抗癌细胞毒药物的非小细胞肺癌(NSCLC)患者的手术标本(鳞状上皮癌)提取癌细胞基因组总DNA。对小鼠成纤维(NIH/3T3)细胞行转染实验。获二轮转化细胞,发现二轮转化率是一轮的2.7倍。在转染过程中转化灶出现的多少,与所用DNA的量有一定关系。 二轮转化细胞能在软琼脂上存活生长,接种裸鼠能长出肿瘤,分离肿瘤组织细胞,体外培养传代存活。表明该二轮转化细胞具有肿瘤细胞的特性。 取一轮、二轮转化细胞和裸鼠肿瘤细胞的DNA分别与放射性~(32)P标记的人体特有的Alu重复序列和ras家族基因探针进行Southern印迹转移和分子杂交。结果在三者细胞的DNA中都见有与Alu杂交的条带。这表明在转染过 程中人体特有的Alu重复序列已整合到转化细胞的基因组中。并确定了转化细胞中的转化基因之一的属性为Ha-ras癌基因。本工作提示吸烟可能是人肺鳞癌发生和Ha-ras活化的重要因素。     

降低mRNA差异显示技术假阳性率的一种方法

为了探讨降低mRNA差异显示技术假阳性率的方法 ,进一步提高此技术的可靠性 ,提取了手术切除肝癌及非癌肝组织成对标本的总RNA ,逆转录获得cDNA片段 ,以mRNA差异显示方法筛选差异表达基因 ,选取较明显的一条差异表达条带 ,行进一步PCR扩增 .分别对PCR产物及其经TA克隆后随机挑选的 6个单克隆质粒DNA进行序列分析 ,并通过GenBank BLAST数据库进行序列的同源性比较 ,以Northern杂交予以来源确认 .自 72 0余条扩增条带中共选出 2 8条差异条带 .序列分析及同源性比较表明 ,所选择条带的PCR产物为一可能的新基因片段 ;而随机选择的 6个TA克隆质粒DNA中 ,有 4个为同一已知基因片段 ,一个为另一已知基因片段 ,一个为一可能的新基因片段 .同源性比较表明 ,PCR产物直接测序所得序列与TA克隆质粒DNA的 6个片段不具同源性 .结果表明 ,mRNA差异显示条带可能由 1条以上分子量相似的片段构成 ,直接对PCR产物行序列分析并以其为探针进行Northern杂交 ,是导致出现假阳性片段的原因之一 .将PCR产物进行TA克隆 ,对单克隆质粒DNA进行序列分析并以其为探针进行Northern杂交 ,可能是解决此问题的一种较好方法 .     

骨髓间充质干细胞和部分肿瘤细胞中Nucleostemin基因的表达

以分离的人胚胎和大鼠骨髓间充质干细胞 (MSCs) ,6种肿瘤细胞株 ,裸鼠肿瘤和转移瘤组织为实验材料 ,以大鼠心肌组织和人胎盘组织为对照 ,探讨nucleostemin基因的表达情况 .RT PCR结果显示 ,nucleostemin基因在MSCs、肿瘤细胞和肿瘤组织中均有不同程度的表达 ,而大鼠心肌和人胎盘组织中无表达 .DNA测序结果证明 ,扩增的PCR产物与GenBank提供的DNA序列完全同源 .SCID裸鼠肿瘤动物模型定量PCR结果证实 ,nucleostemin的mRNA在裸鼠肿瘤组织和转移瘤组织中表达较高 .研究结果表明 ,在细胞中nucleostemin基因不同水平的表达可能与MSCs、肿瘤细胞的增殖和肿瘤的发生、发展与转移有关 .     

人脑原发性肺瘤癌基因的研究——Southern吸印杂交分析

用c-myc、Ha-ras、v-sis及v-erbB四种癌基因为分子探针,对8例人脑原发性肿瘤和两例正常人脑DNA进行Southern吸印杂交分析。结果显示:以c-myc基因为探针进行分子杂交时,所有被检测肿瘤和正常对照都可见一条相同的10.0kb(HindⅢ酶切)人c-myc基因区带。其中一例室管膜瘤和一例脑膜瘤还出现另一条异常的7.0kb(HindⅢ酶切)c-myc基因区带。斑点杂交结果表明,上述两例肿瘤中有c-myc基因的扩增(2—8倍),同时还具有erbB基因的扩增(8倍)。Ha-ras及v-sis基因杂交,未见异常区带。上述结果提示室管膜瘤和脑膜瘤的发生可能与c-myc基因的激活有关;c-myc基因的异常变化与erbB基因扩增同时出现,可能为癌基因之间的协同作用提供证据。     

种子特异性启动子（napinB promoter）分离，表达载体构建及转基因植物获得

利用PCR技术从油菜Brassica napus H165基因组DNA中分离了napinB启动子,序列分析表明,扩增片段（nap300)与文献报道的napinB启动子相应区域的同源性为97％,将其与gus连接构建种子特异性表达载体,农杆菌介导转化烟草,PCR,Southern结果显示,nap300已整合到烟草基因组DNA,获得了转基因植株。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.