柑桔裂皮病类病毒感染爪哇三七叶片原生质体

柑桔裂皮病类病毒(Citrile Exocortis Viroid,简称CEV)是一种严重影响柑桔生产的单链闭环RNA致病因子,近年来人们已对它的理化特性、检测方法以及离体培养系统进行了研究。由于利用原生质体出利用整个植物或愈伤组织来研究CEV复制和致病机理更为优越,所以建立一个适合CEV感染的原生质体体系是人们关心的重要课题。     

柑桔根繁能脱除裂皮病类病毒吗?

柑桔裂皮病类病毒(Citrus Exocortis Vitold,CEV)的传播和流行,对柑桔的生产带来了严重的损失。已证明特CEV的亲本可通过嫁接、插枝这两种营养繁殖的方式将CEV传播给子代。所以,CEV脱毒方法就成为生产上急待解决的问题。据报道,采用热处理、茎尖微芽嫁接和选育珠心苗等技术可获得无毒植株。嫁接是一种常用的育苗方法,然     

柑桔裂皮病类病毒一爪哇三七悬浮细胞的生长特性

爪哇三七(Gvnura aurantlaca Dc)是柑桔裂皮病类病毒(Citrus Exocortis Viroid简称CEV)敏惑的指示植物。用CEV感染的柑桔叶研磨汁液机械接种健康爪哇三七植株,以此作为CEV感染的外植体采源。在MS和B,琼脂培养基上诱导和继代培养健康、CEV感染的爪哇三七叶片的愈伤组织,在MS、B,液体培养基中建立健康、CEX’感染的爪哇三七悬浮细胞系统。从愈伤组织和悬浮细胞培养物中抽提核酸,经5％双向聚丙烯酰胺凝胶电泳、银染分析：在健康爪哇三七愈伤组织和悬浮细晦中不出现特异的CEV电泳带,而CEV感染的爪哇三七的所有培养物中都含有类病毒。cEV可在有丝分裂征盛的爪哇三七悬浮细胞中复制。散伤组织和悬浮细胞很容易继代培养和保存。     

生物素肼化学标记和DIG标记cDNA探针检测柑桔裂皮病类病毒

分别用生物素肼化学标记和ＤＩＧ标记我国柑桔裂皮病类病毒（ＣＥＶｄ）全长克隆ｃＤＮＡ,用以上探讨对不同来源的的核酸样品进行斑点杂交。两种探针可检出病柑桔总核酸的最低含量久为４００ｎｇ／斑点和８０ｎｇ／斑点;生物素肼标记ＣＥＶｄ－ＤＮＡ探讨针,可检出ＣＥＶｄ－ｃＤＮＡ的最低含量约为１０ｐｇ／斑点,研制的ＣＥＶｄ检测试剂盒能检测出发病和隐性带毒苗木中的ＣＥＶｄ,灵敏、特异、简便、快速。试剂盒已使用于检测     

感染柑桔裂皮病类病毒的悬浮细胞的一些特性

爪哇三七(Gynura aurantiaca D.C.)是柑桔裂皮病类病毒(Citrus Exocortis Vi-roid,简称CEV)敏感的指示植物。我们建立了健康和CEV感染的爪哇三七悬浮细胞培养的体外系统。绘制了悬浮细胞培养的生长曲线、pH曲线和温度曲线。CEV可以在悬浮细胞中复制。对继代培养中CEV和寄主核酸的连续测定表明CEV的扩增阻遏了寄主核酸的复制。     

Interference between viroids inducing exocortis and cachexia diseases of citrus

Systemic interactions of long duration among the Group I] Citrus Viroids, CVd-IIa and CVd-IIb were investigated by grafting buds from established citron (Citrus medica L.) sources containing single viroids to a common healthy seedling. In healthy tissues, the two viroids became established in approximately equal titres as a mixed infection. By contrast, tissues that grew from the CVd-IIa or CVd-IIb source buds contained only trace amounts of the heterologous invading viroids. This interference between CVd-IIa, a mild exocortis agent, and CVd-IIb, the cachexia agent, was also demonstrated in the presence of CEVd, the severe exocortis agent but not a Group II viroid. When a CVd-IIb bud was propagated on a citron containing CVd-IIa, a dramatic reduction in the titre of CVd-IIb was observed. The interference between CVd-IIa and CVd-IIb indicates that the mild and relatively innocuous isolate, CVd-IIa, can interfere with the replication and/or accumulation of the severe cachexia agent, CVd-IIb, in citrus. This offers a potential practical approach for the control of cachexia in commercial plantings by “viroid interference”.     

Characterization of Episomal Replication of Bovine Papillomavirus Type 1 DNA in Long-Term Virion-Infected Saccharomyces Cerevisiae Culture

Virologica Sinica - We have previously reported that bovine papillomavirus type 1 (BPV-1) DNA can replicate its genome and produce infectious virus-like particles in short term virion-infected S....     

沙田柚配子体自交不亲和花柱消减文库的构建及分析

分别以沙田柚自交花柱cDNA为tester,异交花柱cDNA为driver,利用抑制性消减杂交技术构建了消减文库,文库的重组率高于95%,插入片段集中在100～500 bp之间,对文库部分克隆进行测序并与GenBank中的同源序列进行比较,发现了一些类似于SI、S9-RNase、激酶类等与自交不亲和相关的基因.     

大鼠老化过程大脑皮层及小脑神经元染色质构象分析

 本文在前文~[2]的基础上进一步以MCN和DNaseⅠ为探针研究大鼠脑神经元终末分化后不同生理时期染色质构象,结果表明:MCN酶解DNA产物PAGE显示脑老化过程大脑皮层及小脑神经元染色质核小体单体DNA分别保持在176bp和215bp水平,核小体连接DNA长度存在组织差异,但不受老化影响;<2>DNaseⅠ酶解DNA产物PAGE显示各年龄组大脑皮层及小脑神经元染色质DNA存在10bp间隔重复结构和相同的泳动区带分布特征,提示脑老化中染色质具有稳定的B型双螺旋结构和一致的螺线管卷曲形式。染色质DNaseⅠ降解率随年龄增加而降低,提示老化导致活性染色质区域减少,老化过程脑神经元染色质构象改变成为其转录功能减退的结构基础。     

Identification of Putative Biomarkers for Toluene-Degrading Burkholderia and Pseudomonads by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry and Peptide Mass Fingerprinting

The use of peptide mass fingerprinting with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was demonstrated to identify and phenotypically characterize toluene-degrading bacteria via biomarkers of degradation and taxonomical classification. Pseudomonas putida F1, P. mendocina KR1, and Burkholderia sp. JS150 were grown on toluene, extracted, electrophoretically separated, and analyzed by MALDI-TOF MS. Catabolic enzymes were identified and results substantiated using tandem MS.     

单性结实和自花授粉结实柑橘果实发育中硼镁营养动态的研究

以单性结实的龟井温州蜜柑和自花授粉结实的鄂柑1号橘为试材,对整个果实发育期的子房(幼果)、果皮和果肉的硼镁含量变化进行了测定。结果表明:1)龟井花前至花期子房硼含量就已较高,花后下降;而鄂柑1号花期子房硼含量相对较低,花后有一显著上升;两品种子房(幼果)镁含量变化无明显差异,花后均趋下降。2)两品种果皮硼含量变幅较小,而果肉硼含量变幅相对较大,且均在果实膨大期出现明显的上升高峰;两品种果皮和果肉镁含量在果实发育前期均相对较高,在果实发育的中后期则趋明显下降。     

Detection and determination of selenoproteins by nuclear techniques

Microbeam X-ray spectrometry, energy-dispersive X-ray fluorescence analysis, and neutron activation analysis were evaluated for the detection of selenium contained in the selenoprotein glutathione peroxidase. The glutathione peroxidase had been previously separated using polyacrylamide gel electrophoresis. The use of Bragg-reflected polarized X-ray beams was employed in the X-ray fluorescence measurements to minimize the problem of scatter owing to the gel matrix. Current detection limits of selenium in a gel matrix are 2.1 ng in the bench-top microbeam X-ray system and 30–60 ng using XRF with polarized beams. Neutron activation analysis was used for qualitycontrol measurements, with a detection limit here of <0.08 ng. The work has in principle established the feasibility of such an approach.     

Effect of disodium fumarate on ruminal metabolism and rumen bacterial communities as revealed by denaturing gradient gel electrophoresis analysis of 16S ribosomal DNA

The aim of the present study was to examine the effects of feeding diets with addition of disodium fumarate (DF) to goats on ruminal metabolism and changes of rumen bacterial communities. Four cannulated goats were used in a 4 × 4 Latin square design. The results showed that ruminal pH increased linearly (P<0.01)as the amount of DF added increased, while lactate production decreased linearly (P<0.01). DF addition did not affect the production of acetate, propionate, butyrate, TVFA and NH₃-N. The effect of DF on the changes in rumen bacterial-community structure of goats was analyzed using 16S rDNA-based approaches. Amplicons of the V6-V8 variable regions of bacterial 16S rDNA were analyzed by denaturing gradient gel electrophoresis (DGGE), cloning and sequencing. Differences in rumen bacterial community structure were determined based on the Shannon index of diversity for pairwise comparison of the DGGE fingerprints and revealed significant changes in rumen microbiota after DF addition. As compared with those fed with the control diet, goats fed on the diets with DF addition showed a higher bacterial diversity. The sequences of seven amplicons in total 11 clones showed less than 97% similarity with those of previously identified or unidentified bacteria, suggesting that most bacteria in the gastrointestinal tract have not been cultured or identified. Amplicons related to Succinivibrio dextrinosolvens species were found in most DGGE fingerprints derived from goats on the diet containing DF, but not in goats on the control diet. These results demonstrated the ability of DF to improve the metabolism of rumen lactate fermentation and to influence the bacterial composition of the rumen in goats.     

Intrinsic protein phosphorylation in synaptic plasma membrane fragments from the rat General characteristics and migration behaviour on polyacrylamide gels of the main phosphate acceptors

Preparations enriched in synaptic membrane fragments from rat cerebral cortex contain protein kinases which phosphorylate membrane proteins in reactions dependent on cAMP, Ca²⁺ (in the absence or presence of calmodulin) or independent of these factors. In these present work characteristics of the main phosphorylated acceptors were studied and compared with the results of other investigations. Apparent molecular weights were estimated by determining electrophoretic mobility on gels of different acrylamide concentration. Irregular migration behaviour was detected by measuring free mobilities from Ferguson plots. Certain phosphate acceptors were found to exhibit anomalously low free mobilities and it was concluded that estimates of molecular weight for these acceptors were unreliable.