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1.
香蕉不同组织中总RNA的有效分离   总被引:12,自引:4,他引:8  
从植物组织中提取总RNA是进行植物分子生物学某些方面研究的必要前提。如进行Northem杂交分析,纯化mRNA以用于体外翻译或建立cDNA文库,RT-PCR及差示分析等分子生物学实验,都需要高质量的总RNA。因此,从植物组织中提取高质量的总RNA是顺利进行上述研究的关键所在。目前常用于植物材料RNA提取的方法有脱法[1~4]苯酚法[5,6]和CTAB[7,8]法等。这些方法对于提取某些植物的总RNA是有效的,但对另外一些植物来说,却并不一定是好的方法。因为不同植物组织的细胞内外成分复杂多变,在使…  相似文献   

2.
双链RNA技术在植物病毒研究中的应用   总被引:19,自引:0,他引:19  
含RNA基因组的植物病毒在复制时会产生双链RNA(dsRNA)。本文介绍了用CF--11纤维素粉提取dsRNA的步骤,并列举了dsRNA在植物病毒研究中的应用,其主要应用有(1)用于检测植物病毒;(2)用于病毒株系分化;(3)用于病毒卫星RNA及亚基因组RNA研究;(4)用于侵染性测定及病毒基因组功能研究等。  相似文献   

3.
植物抗病毒基因工程育种策略及其进展   总被引:10,自引:0,他引:10  
简要讨论了近年来植物抗病毒基因工程育种策略。这些策略包括利用植物自身的抗病毒基因;利用病毒宙蛋白基因、动物蛋白基因、复制酶基因、卫星RNA、反义链RNA和缺陷干扰型RNA;利用抗体基因、核酶和干扰素。并以各种策略的抗病毒机理及其在农业生产上的应用前景进行了讨论。  相似文献   

4.
RNA地位上升     
人们长期认为核糖核酸 (RNA)在细胞中只传递信息和氨基酸 ,但最近因它的多功能而令人瞩目。自 1995年表明小分子RNA能够关闭一种线虫中的基因 ,与植物中已知的“基因沉默”(genesilence)相似 ,分子生物学家即认识到基因功能研究将因“RNA干扰”(RNAinterference ,RNAi)而得益 ,对RNA的兴趣飙升。 2 0 0 1年他们发现RNAi也能在鼠和人的细胞中阻遏基因的活性。小分子RNA起着重要的生物作用 ,从DNA序列分析已知线虫和果蝇中有几十个 ,大肠杆菌有数百个 ,鼠脑组织更多。在线虫和果蝇中 ,这…  相似文献   

5.
果实成熟的基因工程研究   总被引:6,自引:0,他引:6  
乙烯是催化果实成熟的内源植物激素。本文简要介绍用植物基因工程的手段分离和鉴定出乙烯合成和果实成熟有关的多聚半乳糖醛酸酶、ACC氧化酶、ACC合酶及ACC脱氨酶的基因。并利用反意RNA技术将它们的反意RNA转入番茄中,得到了相应的反意转基因植株和果实,实现了在基因水平上对果实成熟的调控,开辟了植物育种的新途径。  相似文献   

6.
发夹核酶的研究与应用   总被引:2,自引:0,他引:2  
核酶 (ribozyme)是既能特异识别又能特异切割小分子RNA的核酸内切酶 ,其本身也是RNA ,主要包括发夹核酶、锤头核酶、丁肝病毒、链孢霉属VS和铅依赖性RNA ,共同特点是可逆地切割底物RNA的磷酸二酯键 ,生成 5′ OH和 2′ ,3′ 环磷酸末端。虽然催化产物相似 ,但它们的结构和催化机制却是很不相同的。发夹核酶 (hairpinribozyme)发现于三种不同植物RNA病毒 ,即烟草环点病毒 (tobac coringspotvirus) ,菊苣黄色斑点病毒型 (chico ryyellowmottlevirust…  相似文献   

7.
蝶兰胚珠发育过程中总RNA、Poly+RNA和PolyA-RNA的变化张宪省,马小杰,阎先喜,邢树平(山东农业大学基础部,泰安271018)近年来随着植物分子生物学理论和技术的发展,人们已将分子生物学技术应用于研究植物的生殖。目前已在基因调控花的分化...  相似文献   

8.
反义RNA调控的不同方式   总被引:4,自引:0,他引:4  
宫明  宫锋 《生命的化学》1996,16(4):17-18
反义RNA调控的不同方式宫明,宫锋(山东大学微生物系,济南250100)关键词反义RNA,调控方式反义RNA最早发现于原核生物,但是1986年Williams发现真核细胞中也存在天然反义RNA。不同的反义RNA其功能和作用方式不尽相同,它们控制着噬菌...  相似文献   

9.
同时抽提DNA和RNA的简便方法   总被引:1,自引:0,他引:1  
同时抽提DNA和RNA的简便方法刘定干(中国科学院上海生物化学研究所,200031)关键词DNARNA抽提在研究工作中,常同时需要培养细胞的DNA和RNA,从同一样品中同时提取DNA和RNA。目前,已有好几种同时抽提DNA和RNA的方法[1~4]。作...  相似文献   

10.
AGPC法是一种快速、简便、有效的RNA提取方法。参照该法自新生大鼠脑组织中提取出总RNA,进一步通过oligo(dT)-纤维素亲和层析分离获得poly(A) ̄+RNA。当poly(A) ̄+RNA或总RNA经显微注射法进入非洲爪蟾卵母细胞后,其翻译系统能够利用外源mRNA合成具有催化活性的胆碱酯酶。表达的胆碱酯酶大部分分泌到卵母细胞培养液中。在一定范围内,mRNA的注射量与胆碱酯酶的表达量成正比。所合成的胆碱酯酶活性可被毒扁豆碱和S-(2-二异丙基氨乙基)甲基硫赶膦酸乙酯(VX)抑制。  相似文献   

11.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

12.
Extracellular (EC) adenosine, hypoxanthine, xanthine, and inosine concentrations were monitored in vivo in the striatum during steady state, 15 min of complete brain ischemia, and 4 h of reflow and compared with purine and nucleotide levels in the tissue. Ischemia was induced by three-vessel occlusion combined with hypotension (50 mm Hg) in male Sprague-Dawley rats. EC purines were sampled by microdialysis, and tissue adenine nucleotides and purine catabolites were extracted from the in situ frozen brain at the end of the experiment. ATP, ADP, and AMP were analyzed with enzymatic fluorometric techniques, and adenosine, hypoxanthine, xanthine, and inosine with a modified HPLC system. Ischemia depleted tissue ATP, whereas AMP, adenosine, hypoxanthine, and inosine accumulated. In parallel, adenosine, hypoxanthine, and inosine levels increased in the EC compartment. Adenosine reached an EC concentration of 40 microM after 15 min of ischemia. Levels of tissue nucleotides and purines normalized on reflow. However, xanthine levels increased transiently (sevenfold). In the EC compartment, adenosine, inosine, and hypoxanthine contents normalized slowly on reflow, whereas the xanthine content increased. The high EC levels of adenosine during ischemia may turn off spontaneous neuronal firing, counteract excitotoxicity, and inhibit ischemic calcium uptake, thereby exerting neuroprotective effects.  相似文献   

13.
At one spectrum extreme, Astrobiology conjectures that for exoplanets with Goldilocks conditions, terrestrial-like life is inevitable. Moreover, it is envisaged that via panspermia, terrestrial-like life and its precursors are transferred among galaxies, stars, and within solar systems via transiting comets, asteroids, and planetoids. In addition, expelled stars, which have solar systems, it is inferred, transfer life as well. However, at the other extreme, we propose a paradigm shift that on some planets, subject to non- Goldilocks conditions, metal machine life could arise, ab initio, and evolve viruses, intelligence, and civilizations, conjointly. Accordingly, intelligent mechanized civilizations could readily and efficiently commence space exploration. Furthermore, as a counter paradigm shift, such civilizations could experiment and produce non-metallic life, based on carbon and other non-metal elements, under suitable conditions, related to Goldilocks life. Even a single example of validated interstellar or intergalactic communication received on the Earth would support the existence of life elsewhere. However, the communication platform should not be restricted to electromagnetic radiation. Other platforms should be included as well - one such example, which would require sophisticated technology, is neutrino communication. This is the case for any advanced civilization, be it metal-machine based, biological-based, and carbon-based. In sum, civilizations based on machine life, would be highly productive due to the longevity and hardiness of machine life. However, significant caveats are raised in this brief report, because possibly dissimilar psychologies and intelligence may lead to conflicts between metal machine life and biological life, inter-paradigm conflict.  相似文献   

14.
This study describes a method for predicting and classifying oxygen-binding pro- teins. Firstly, support vector machine (SVM) modules were developed using amino acid composition and dipeptide composition for predicting oxygen-binding pro- teins, and achieved maximum accuracy of 85.5% and 87.8%, respectively. Sec- ondly, an SVM module was developed based on amino acid composition, classify- ing the predicted oxygen-binding proteins into six classes with accuracy of 95.8%, 97.5%, 97.5%, 96.9%, 99.4%, and 96.0% for erythrocruorin, hemerythrin, hemo- cyanin, hemoglobin, leghemoglobin, and myoglobin proteins, respectively. Finally, an SVM module was developed using dipeptide composition for classifying the oxygen-binding proteins, and achieved maximum accuracy of 96.1%, 98.7%, 98.7%, 85.6%, 99.6%, and 93.3% for the above six classes, respectively. All modules were trained and tested by five-fold cross validation. Based on the above approach, a web server Oxypred was developed for predicting and classifying oxygen-binding proteins(available from http://www.imtech.res.in/raghava/oxypred/).  相似文献   

15.
随着智能手机和人工智能技术的发展, 以手机app为载体的植物识别软件慢慢走进公众生活、科普活动和科研活动的各个方面。植物识别app的识别正确率是决定其使用价值和用户体验的关键因素。目前, 国内应用市场上有许多植物识别app, 它们的开发目的和应用范围各异, 软件本身的关注点、数据库来源、算法、硬件要求也存在很大差异。对于不同人群, 植物识别app有不同的意义, 如对于科研人员来说, 识别能力强的app是提高效率的一大工具; 对植物爱好者来说, 具一定准确率的识别app可以作为入门的工具。因此, 对各app的识别能力进行分析与评价显得尤为重要。本文选取了8款常用的app, 分别对400张已准确鉴定的植物图片进行识别, 其中干旱半干旱区、温带、热带和亚热带4个区各选取100张。这些图片共计122科164属340种, 涵盖了乔木、灌木、草本、草质藤本和木质藤本5种生长型, 包含23种国家级保护植物。种、属、科准确识别正确分别计4分、2分、1分, 以此标准对软件识别能力按总得分进行排序, 正确率得分由高到低依次为花帮主、百度识图、花伴侣、形色、花卉识别、植物识别、发现识花、微软识花。  相似文献   

16.
海蛎是一种营养和医药价值较高的咸水双壳类动物,在世界各地被广泛养殖。海蛎壳副产品是一种天然生物质资源,由95%的碳酸钙和5%的有机基质组成。海蛎壳的多尺度、多层次“砖-泥”独特结构,使其具有良好的机械稳定性、生物相容性、可降解性和优异的吸附特性。首先,介绍了海蛎壳生物质的理化性质和天然独特微纳米结构,总结了海蛎壳在农业、工业、生物医药领域的研究现状,详细阐述了其在污水治理、土壤改良、天然抗菌剂(食品工业和生物医药)、骨组织工程、医药原料、生物填料、工业催化剂及分散载体、建筑工业填料、功能化涂料等领域的研究现状。其次,概述了利用生物转化技术将海蛎壳转化为生物能源、新型生物质材料等方面的研究进展。最后,展望了海蛎壳生物质资源及其衍生物未来在工业、农业、医药领域的潜在应用。  相似文献   

17.
The levels of bioactive anthocyanins in the fruits of Amelanchier alnifolia, A. arborea and A. canadensis have been determined by HPLC. Cyanidin 3-galactoside (1) was present in the fresh fruit of the three species at concentrations of 155, 390 and 165 mg/100 g, respectively. Cyanidin 3-glucoside (2) was present only in A. alnifolia and A. canadensis at concentrations of 54 and 48 mg/100 g, respectively. The anthocyanins were confirmed by LC-ESI/MS and NMR studies. At 100 ppm, anthocyanin mixtures from the three species inhibited cyclo-oxygenase (COX)-1 and -2 enzymes at 66 and 67%, 60 and 72%, and 51 and 76%, respectively. The positive controls used in the COX assays were aspirin, Celebrex and Vioxx at 180, 1.67 and 1.67 ppm, respectively, and showed 74 and 69%, 5 and 82% and 0 and 85% COX-1 and COX-2 inhibition, respectively. Anthocyanins 1 and 2 and cyanidin (3) inhibited COX-1 enzyme 50.5, 45.62 and 96.36%, respectively, at 100 ppm, whereas COX-2 inhibition was the highest for 3 at 75%. In the lipid peroxidation inhibitory assay, anthocyanin mixtures at 10 ppm from the three species showed activities of 72, 73 and 68%, respectively, compared with 89, 87 and 98% for commercial anti-oxidants butylated hydoxyanisole, butylated hydroxytoluene, and tert-butylhydroxyquinone at 1.67, 2.2 and 1.67 ppm, respectively. At 10 ppm, compounds 1-3 inhibited lipid peroxidation by 70, 75 and 78%, respectively.  相似文献   

18.
林有润 《植物研究》2002,22(3):341-365
棕榈科原省藤亚科因其子房壁及外果皮被倒生、螺旋状排列的鳞片所覆盖,而区别于其他亚科,因而独立分出成一新科--省藤科。作者讨论了棕榈科的祖先种可能在石炭纪时,自原始裸子植物开以顿目在分化、衍生出苏铁目祖先种的进化干上,于白垩纪时分化出的一个分支。在棕榈科的祖先种出现不久后,在其进化的分支上,于白垩纪后期又分化出一旁支,成为棕榈科的姊妹科--省藤科的祖先种。从两祖先种分别再分化、衍生出现今分布地球上该二科的属与种。两科、尤其前者是被子植物、尤其是单子叶植物中最原始的类群之一。作者还提出棕榈科象牙椰亚科与贝叶棕亚科是该科最原始或较原始的两类群;槟榔亚科和腊材榈亚科是较进化的两类群;而水椰亚科祖先种可能源于象牙椰亚科的祖先种,但又演化为该科最进化与特化的类群。省藤科省藤亚科略比鳞果榈亚科原始。作者讨论了两科为泛热带分布的科,指出两科的"现代分布区"在南北两半球热带地区,少数种还延伸分布到两半球暖亚热带、甚至达中亚热带地区,分布区边缘最北达日本中部、中国长江流域及黄河下游的南部,美国加利佛尼亚州与佛罗里达州和地中海北部;最南达智利中部和新西兰南部;而"现代分布中心"在热带与暖亚热带的亚洲,中、南美洲,大洋洲及非洲的东、南、西部;但分布区的"密集中心"则在热带亚洲、热带中及南美洲、南太平洋群岛及非洲东南部。作者还介绍了近50年我国南方引种驯化成功的两科植物近400种(见*图谱),其中少数为耐寒的种类,有的种已引种到长江流域或更北的地区。引种的大部分种都有其重要的经济用途,包括:1. 食用,如淀粉和树液可制"西米"或制糖,酿酒、醋或作饮料;果或种子榨油,供食用或工业用;某些种的嫩芽作蔬菜,甚至种子代咖啡饮用;2. 药用,有消炎、止血、活血、驱虫、抗癌等用;3. 建筑、工艺与日用品,包括不少种的树干供建普通房子、桥梁、小船;少数种可提制工业用蜡;许多种的纤维制高级缆绳和编织品;还制工艺品与日用品等;4. 代表热带景观的园林工程、绿化及美化环境的观赏树和人行道树及建造园林景观生态类型的树种等。  相似文献   

19.
People with severe mental illness have a considerably shorter lifespan than the general population. This excess mortality is mainly due to physical illness. Next to mental illness‐related factors, unhealthy lifestyle, and disparities in health care access and utilization, psychotropic medications can contribute to the risk of physical morbidity and mortality. We systematically reviewed the effects of antipsychotics, antidepressants and mood stabilizers on physical health outcomes in people with schizophrenia, depression and bipolar disorder. Updating and expanding our prior systematic review published in this journal, we searched MEDLINE (November 2009 ‐ November 2014), combining the MeSH terms of major physical disease categories (and/or relevant diseases within these categories) with schizophrenia, major depressive disorder and bipolar disorder, and the three major psychotropic classes which received regulatory approval for these disorders, i.e., antipsychotics, antidepressants and mood stabilizers. We gave precedence to results from (systematic) reviews and meta‐analyses wherever possible. Antipsychotics, and to a more restricted degree antidepressants and mood stabilizers, are associated with an increased risk for several physical diseases, including obesity, dyslipidemia, diabetes mellitus, thyroid disorders, hyponatremia; cardiovascular, respiratory tract, gastrointestinal, haematological, musculoskeletal and renal diseases, as well as movement and seizure disorders. Higher dosages, polypharmacy, and treatment of vulnerable (e.g., old or young) individuals are associated with greater absolute (elderly) and relative (youth) risk for most of these physical diseases. To what degree medication‐specific and patient‐specific risk factors interact, and how adverse outcomes can be minimized, allowing patients to derive maximum benefits from these medications, requires adequate clinical attention and further research.  相似文献   

20.
Summary This review is given on the origin and interrelationship of blackgram and greengram: the symptoms, mode of transmission, and host range of important diseases, namely: mungbean yellow mosaic virus, leaf crinkle virus, leaf curl virus, mosaic mottle virus, Cercospora leaf spot, powdery mildew, root and stem rots, bacterial leaf spot and halo blight. The screening for resistance, sources of resistance, including interspecific hybridization, and induced mutations, as well as the genetics of resistance are treated along with suggestions for future breeding strategies of these crops.Greengram is relatively drought tolerant. It is cultivated in India, Pakistan, Bangladesh, Srilanka, Thailand, Laos, Kampuchea, Vietnam, eastern Malaysia, Southern China and in the relatively dry eastern parts of Java, (Jain and Mehra 1978). In the recent past it has been introduced into the eastern and central parts of Africa, the West Indies and the U.S.A. It is also grown in the Philippines, Nepal, Taiwan and Indonesia. Blackgram has greater water requirements than greengram. It is grown in India, Pakistan, Srilanka and Burma (Jain and Mehra 1978).  相似文献   

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