香蕉不同组织中总RNA的有效分离

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…     

双链RNA技术在植物病毒研究中的应用

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。     

植物抗病毒基因工程育种策略及其进展

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。     

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…     

果实成熟的基因工程研究

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。     

发夹核酶的研究与应用

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…     

蝶兰胚珠发育过程中总RNA、Poly＋RNA和PolyA－RNA的变化

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...     

反义RNA调控的不同方式

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...     

同时抽提DNA和RNA的简便方法

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...     

大鼠胆碱酯酶mRNA在卵母细胞中的表达

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。     

Accumulation of Minerals by Leccinum scabrum from Two Large Forested Areas in Central Europe: Notecka Wilderness and Tuchola Forest (Pinewoods)

Leccinum scabrum sporocarps and associated topsoils from two areas in Poland have been characterized for contents and bioconcentration potential of Ag, Al, Ba, Ca, Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr and Zn. Topsoil and fruitbody element composition varied between the two study sites, most likely as a result of local soil geochemistry. Element content of the labile fraction in topsoil from both sites followed the ‘pseudo‐total’ fraction and median values (mg kg^?1 dry matter) were: K 380 and 340, Mg 760 and 840, P 1100 and 920, Al 3800 and 8100, Ag 0.31 and 0.28, Ba 28 and 37, Ca 920 and 790, Cd 0.23 and 0.23, Co 2.0 and 1.7, Cu 3.2 and 3.6, Fe 2800 and 6300, Mn 280 and 180, Na 99 and 110, Ni 7.8 and 8.8, Pb 12 and 18, Rb 1.3 and 2.1, Sr 4.8 and 4.0 and Zn 22 and 19, respectively. Only for some elements such as K, Mg, Al, Ag, Ca, Co, Mn, Na, Ni, Sr and Zn we found concentration differences between the two study sites for the caps of sporocarps. With the exception of Al, Mn, Na and Pb, stipes showed a similar tendency. Caps had a higher concentration of K, Rb, P, Mg, Al, Ag, Cu, Fe, Zn, Cd, Pb and Ni compared to stipes, while Na, Ba and Sr contents were higher in stipes. The comparison of soil and fruitbody concentrations indicates that L. scabrum bioconcentrate some elements while others are bioexcluded.     

Validity and utility of Hierarchical Taxonomy of Psychopathology (HiTOP): I. Psychosis superspectrum

The Hierarchical Taxonomy of Psychopathology (HiTOP) is a scientific effort to address shortcomings of traditional mental disorder diagnoses, which suffer from arbitrary boundaries between psychopathology and normality, frequent disorder co‐occurrence, heterogeneity within disorders, and diagnostic instability. This paper synthesizes evidence on the validity and utility of the thought disorder and detachment spectra of HiTOP. These spectra are composed of symptoms and maladaptive traits currently subsumed within schizophrenia, other psychotic disorders, and schizotypal, paranoid and schizoid personality disorders. Thought disorder ranges from normal reality testing, to maladaptive trait psychoticism, to hallucinations and delusions. Detachment ranges from introversion, to maladaptive detachment, to blunted affect and avolition. Extensive evidence supports the validity of thought disorder and detachment spectra, as each spectrum reflects common genetics, environmental risk factors, childhood antecedents, cognitive abnormalities, neural alterations, biomarkers, and treatment response. Some of these characteristics are specific to one spectrum and others are shared, suggesting the existence of an overarching psychosis superspectrum. Further research is needed to extend this model, such as clarifying whether mania and dissociation belong to thought disorder, and explicating processes that drive development of the spectra and their subdimensions. Compared to traditional diagnoses, the thought disorder and detachment spectra demonstrated substantially improved utility: greater reliability, larger explanatory and predictive power, and higher acceptability to clinicians. Validated measures are available to implement the system in practice. The more informative, reliable and valid characterization of psychosis‐related psychopathology offered by HiTOP can make diagnosis more useful for research and clinical care.     

Discovery of ancestral L-ornithine and L-lysine decarboxylases reveals parallel,pseudoconvergent evolution of polyamine biosynthesis

Polyamines are fundamental molecules of life, and their deep evolutionary history is reflected in extensive biosynthetic diversification. The polyamines putrescine, agmatine, and cadaverine are produced by pyridoxal 5′-phosphate-dependent L-ornithine, L-arginine, and L-lysine decarboxylases (ODC, ADC, LDC), respectively, from both the alanine racemase (AR) and aspartate aminotransferase (AAT) folds. Two homologous forms of AAT-fold decarboxylase are present in bacteria: an ancestral form and a derived, acid-inducible extended form containing an N-terminal fusion to the receiver-like domain of a bacterial response regulator. Only ADC was known from the ancestral form and limited to the Firmicutes phylum, whereas extended forms of ADC, ODC, and LDC are present in Proteobacteria and Firmicutes. Here, we report the discovery of ancestral form ODC, LDC, and bifunctional O/LDC and extend the phylogenetic diversity of functionally characterized ancestral ADC, ODC, and LDC to include phyla Fusobacteria, Caldiserica, Nitrospirae, and Euryarchaeota. Using purified recombinant enzymes, we show that these ancestral forms have a nascent ability to decarboxylate kinetically less preferred amino acid substrates with low efficiency, and that product inhibition primarily affects preferred substrates. We also note a correlation between the presence of ancestral ODC and ornithine/arginine auxotrophy and link this with a known symbiotic dependence on exogenous ornithine produced by species using the arginine deiminase system. Finally, we show that ADC, ODC, and LDC activities emerged independently, in parallel, in the homologous AAT-fold ancestral and extended forms. The emergence of the same ODC, ADC, and LDC activities in the nonhomologous AR-fold suggests that polyamine biosynthesis may be inevitable.     

Form and function of tentacles in pteriomorphian bivalves

Tentacles are remarkable anatomical structures in invertebrates for their diversity of form and function. In bivalves, tentacular organs are commonly associated with protective, secretory, and sensory roles. However, anatomical details are available for only a few species, rendering the diversity and evolution of bivalve tentacles still obscure. In Pteriomorphia, a clade including oysters, scallops, pearl oysters, and relatives, tentacles are abundant and diverse. We investigated tentacle anatomy in the group to understand variation, infer functions, and investigate patterns in tentacle diversity. Six species from four pteriomorphian families (Ostreidae, Pinnidae, Pteriidae, and Spondylidae) were collected and thoroughly investigated with integrative microscopy techniques, including histology, scanning electron microscopy, and confocal microscopy. Tentacles can be classified as middle fold tentacles (MFT) and inner fold tentacles (IFT) according to their position with respect to the folds of the mantle margin. While MFT morphology indicates intense secretion of mucosubstances, no evidence for secretory activity was found for IFT. However, both tentacle types have appropriate ciliary distribution and length to promote mucus transportation for cleaning and lubrication. Protective and sensory functions are discussed based on different lines of evidence, including secretion, cilia distribution, musculature, and innervation. Our results support the homology of MFT and IFT only for Pterioidea and Ostreoidea, considering their morphology, the presence of ciliated receptors at the tips, and branched innervation pattern. This is in accordance with recent phylogenetic hypotheses that support the close relationship between these superfamilies. In contrast, major structural differences indicate that MFT and IFT are probably not homologous across all pteriomorphians. By applying integrative microscopy, we were able to reveal anatomical elements that are essential for the understanding of homology and function when dealing with such superficially similar structures.     

Revision of the Athyrisininae, Siluro-devonian Brachiopods from China and Russia

Athyrisinine brachiopods from the Upper Silurian of Russia and the Lower–Middle Devonian of China and north Vietnam include over 70 species belonging to Athyrisina and Parathyrisina ; generic and subfamilial diagnoses are emended. Five genera are considered synonyms of Athyrisina and three of Parathyrisina . A neotype is selected and illustrated for Athyrisina squamosa , the type species of Athyrisina . Four nomina nova , Athyrisina xui , Parathyrisina wani , P. minima , and P. cheni , are suggested as new substitute names for Athyrisina tumida Wang, in Xu et al. 1978 (primary homonymy), Athyrisinoides ganxiensis Wan, in Xu et al. 1978, Parathyrisina minor Zhang, in Zhang and Fu 1983, and Athyrisinoides tudilingensis Chen, 1979 (secondary homonyms) respectively. A new genus, Bruntosina , is described from the Emsian to Eifelian of the Qinling region. A new subfamily, Homeathyridinae, is erected within the Athyrididae with Homeathyris , Pseudohomeospira , and Squamathyris included, revised and their diagnoses emended. Homeathyris incisus sp. nov. is described from the Ludfordian of Novaya Zemlya. Ikella is revised and excluded from the athyrisinins. The origin and dispersal of the homeathyridins and the athyrisinins are discussed.     

Dual actions of nitric oxide on angiogenesis: possible roles of PKC, ERK, and AP-1

Regulation of angiogenesis by nitric oxide (NO) is controversial since NO has been shown to have both pro- and anti-angiogenic effects. In this study, we examined the effect of the NO donor, S-nitro-N-acetyl-penicillamine (SNAP), on in vitro angiogenesis, and the mechanisms involved: PKC activity, ERK and c-Jun phosphorylation, and AP-1 DNA binding activity, in microvascular endothelial cells. SNAP, at 0.5-4 mM, significantly and dose-dependently inhibited angiogenesis, PKC activity, and ERK and c-Jun phosphorylation up to 80%, 83%, and 63% and 73%, respectively. SNAP at concentrations > 2mM also abolished AP-1 binding activity. Lower concentrations of SNAP (0.1-0.3 mM) significantly increased angiogenesis, PKC activity, and ERK and c-Jun phosphorylation up to 46%, 60%, and 61% and 180%, respectively. These findings indicate that the dual pro- and anti-angiogenic actions of NO are dose-dependent and suggest that they are mediated by PKC and ERK acting on AP-1.     

自然保护区生态旅游对野生动物的影响

目前中国的很多自然保护区开展了生态旅游,但这类活动对野生动物的影响研究却十分薄弱,因此十分有必要在介绍欧美、澳洲学者的研究进展基础上,针对我国的研究现状,提出该领域的研究方向、监测和管理策略.自然保护区的生态旅游活动主要有野生动物观赏、徒步行走、摄影、野外宿营、山地车或雪地车、电动或机动艇游湖、溪涧漂流、环境教育、社区访问等,旅游活动类型、范围、强度、时空分布等是影响对野生动物干扰大小的主要因素.生态旅游对野生动物的影响包括直接影响(个体的行为反应和生理指标改变、繁殖力降低、种群分布和物种组成的改变等)和间接影响(生境破坏、外来种散布和环境污染等).国外生态旅游对鸟类的影响研究较多,主要集中鸟类的惊飞反应、取食、能量消耗、繁殖等方面;对兽类影响的研究主要集中在行为、生理指标改变、种群数量等方面.我国未来的研究应注重收集基础性研究数据和深入探讨一些理论与应用问题,要运用多种技术手段对自然保护区野生动物的行为、生理、种群动态、物种多样性、生境质量、游客的时空分布、态度和行为等进行长期监测,而后将其结果应用到野生动物、生境以及游客的管理决策中去.另外,研究中应重视自然科学和社会科学的多学科交叉融合.     

Nutritional requirements of Pochonia chlamydospora and ARF18, fungal parasites of nematode eggs

Twenty carbohydrates (C), 18 nitrogen compounds (N), and 9 vitamins were examined for their effects on the growth and conidiation of the nematode-egg-parasitic fungi Arkansas Fungus 18 (ARF18, isolate 908) and Pochonia chlamydospora var. chlamydospora in solid and liquid cultures. Glycogen was the best, and inulin, D-(+)-galactose, and soluble starch were good C sources for the growth of ARF18 in both solid and liquid cultures. ARF18 could not utilize alpha-cellulose in liquid; alpha-lactose and D-mannitol in solid; and D-(+)-xylose, L-(-)-sorbose, and D-(-)-ribose in both solid and liquid cultures. Casein was the best N source for ARF18 growth in both solid and liquid cultures and L-aspartic acid, DL-glutamic acid, peptone, and L-histidine were good in solid culture. ARF18 could not utilize L-cystine and L-tyrosine in solid culture, and L-cystine, DL-methionine, peptone, L-proline, and ammonium nitrate in liquid culture. Supplement of vitamins appeared to be unnecessary for ARF18 to grow. For P. chlamydospora var. chlamydospora growth, all test C sources, except L-(-)-sorbose, alpha-cellulose, citric acid, and D-(+)-glucose, were good in both solid and liquid cultures. Most N compounds were good for P. chlamydospora var. chlamydospora growth with casein and peptone the best. Vitamins had limited effect on P. chlamydospora var. chlamydospora growth. P. chlamydospora var. chlamydospora conidiation was well supported by D-(-)-ribose, D-(-)-fructose, melibiose, and D-(+)-galactose as C sources and by L-aspartic acid, DL-glutamic acid, and L-arginine as N sources. Excluding myo-inositol from the medium containing all other test vitamins increased P. chlamydospora var. chlamydospora conidiation, while excluding pyridoxine appeared to reduce its conidiation.     

Endogenous Opiates: 1996

Olson, G. A., R. D. Olson and A. J. Kastin. Endogenous opiates: 1996. Peptides 18(10) 1651–1688, 1997.—This paper is the nineteenth installment of our annual review of research concerning the opiate system. It summarizes papers published during 1996 reporting the behavioral effects of the opiate peptides and antagonists, excluding the purely analgesic effects, although stress-induced analgesia is included. The specific topics covered this year include stress, tolerance and dependence; eating; drinking; gastrointestinal, renal, and hepatic function; mental illness and mood; learning, memory, and reward; cardiovascular responses; respiration and thermoregulation; seizures and other neurological disorders; electrical-related activity; general activity and locomotion; sex, pregnancy, and development; immunological responses; and other behaviors.     

贵州罗甸纳水上石炭统(宾夕法尼亚亚系)地层的再研究

本文详细描述了贵州罗甸纳水上石炭统(宾夕法尼亚亚系)剖面的生物地层和年代地层,其牙形刺序列自上而下可详细划分为：Streptognathodus isolatus, S. wabaunsensis, S. tenuialveus, S. firmus, Idiognathodus nashuiensis , Streptognathodus simulator, S. guizhouensis , S. gracilis-S, excelsus , S. cancellosus , S. clavatulus , S. nodocarinatus , Idiognathodus podolskensis , Mesogondolella clarki -Idiognathodus robustus , Diplognathodus ophanus-D, ellesmerensis, Idiognathoides ouachitensis, Streptognathodus expansus, Idiognathoides sulcatus parva, Idiognathodus primulus-Neognathodus bassleri, Idiognathodus primulus-Neognathodus symmetricus, Neognathodus symmetricus, Idiognathoides corrugatus-I, pacificus, I. sinuatus, I. sulcatus sulcatus, Declinognathodus noduli ferus 和 Gnathodus bilineatus bollandensis 等带。 Declinognathodus noduliferus 和 Streptognathodus isolatus 的首次出现分别代表上石炭统(宾夕法尼亚亚系)和二叠系的开始。根据牙形刺和有孔虫的序列,罗甸纳水剖面的上石炭统(宾夕法尼亚亚系)地层自下而上可划分为罗苏阶(Luosuan)、滑石板阶(Huashibanian)、达拉阶(Dalaan)和马平阶(Mapingian),并可与俄罗斯的巴什基尔阶(Bashkirian)、莫斯科阶(Moscovian)、卡西莫夫阶(Kasimovian)和格舍尔阶(Gzhelian),北美的莫罗阶(Morrowan)、阿托克阶(Atokan)、得梅因阶(Desmoinesian)、密苏里阶(Missourian)和弗吉尔阶(Virgilian)进行对比。另外,本文也详细讨论了剖面中的石炭系中间界线及石炭-二叠系界线。