Calyculins and Related Marine Natural Products as Serine-Threonine Protein Phosphatase PP1 and PP2A Inhibitors and Total Syntheses of Calyculin A,B, and C

Calyculins, highly cytotoxic polyketides, originally isolated from the marine sponge Discodermia calyx by Fusetani and co-workers, belong to the lithistid sponges group. These molecules have become interesting targets for cell biologists and synthetic organic chemists. The serine/threonine protein phosphatases play an essential role in the cellular signalling, metabolism, and cell cycle control. Calyculins express potent protein phosphatase 1 and 2A inhibitory activity, and have therefore become valuable tools for cellular biologists studying intracellular processes and their control by reversible phosphorylation. Calyculins might also play an important role in the development of several diseases such as cancer, neurodegenerative diseases, and type 2-diabetes mellitus. The fascinating structures of calyculins have inspired various groups of synthetic organic chemists to develop total syntheses of the most abundant calyculins A and C. However, with fifteen chiral centres, a cyano-capped tetraene unit, a phosphate-bearing spiroketal, an anti, anti, anti dipropionate segment, an α-chiral oxazole, and a trihydroxylated γ-amino acid, calyculins reach versatility that only few natural products can surpass, and truly challenge modern chemists’ asymmetric synthesis skills.     

籼型三系不育系丰海A的选育

随着海南省农业结构的优化调整,粮食市场的开拓,杂交稻产业集群的发展要求。海南省农科院粮作所用保持系珍汕97B,枝B,冈B进行复合杂交,把多个亲本的优良特性综合到保持系丰海B中,经5a13代的测交,择优回交,转育成感温型籼稻三系不育系丰海A。     

A re-evaluation of the Dionne method of vegetatively doubling the chromosome number in potato

Summary The efficiency of a published method (Dionne) of vegetatively doubling diploid potato clones by treating the nodal sub-axillary meristems of grafts with colchicine was investigated. Calculations of shoots per graft, tubers per shoot, tuber losses, and doubling frequencies in the three germ layers (LI, LII and LIII) of plants grown from tubers, indicated that one might expect 0.5 completely doubled plants per graft. Clone/shoot regeneration interactions etc. will greatly affect the efficiency in specific cases. LI (epidermis) of plants in the tuber generation was doubled more frequently than LII (hypodermis) and there was a tendency for plants doubled in LI to be also doubled in LII. LII and LIII (internal tissues) usually had the same ploidy. It is argued that the ploidy analysis of plants would have maximum efficiency if LII were screened first whenever possible.

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Zusammenfassung Es werden Daten gegeben, um die Wirksamkeit einer Methode der vegetativen Verdopplung (Dionne) bei Kartoffeln (früher beschrieben von Ross et al., 1967) quantitativ zu bestimmen. Die Methode umfasst die Colchizin-Behandlung (0,25% w?sseriges Colchizin/48 Std.) der nodalen achselst?ndigen Meristeme, die sich an der Basis der Pseudonebenbl?ttchen von Kartoffeltrieben befinden, die auf Tomatenwurzelstücke gepfropft wurden. Tabelle 1 zeigt, dass im Durchschnitt 10,8 bis 22,0% der behandelten Meristeme neue Triebe erzeugten. Die h?chste Zahl wurde mit virusfreien (B) Klonen erreicht. Diese Zahl war nahezu gleich wie die von Ross et al. erhaltene. Es gab grosse Unterschiede in der Erneuerungsrate zwischen den Klonen. Aus Tabelle 2 ist zu ersehen, dass zwischen 31,7 und 51,3% der Triebe, nach Bewurzelung und Eintopfen, keine Knollen erzeugten. Ross et al. berichten von einem Verlust an Trieben in gleichem Umfang. Die Verluste werden haupts?chlich dem sp?ten Auspflanzen vieler Triebe, der Ueberdosierung bei der Behandlung mit Colchizin und einem genotypischen Einfluss zugeschrieben. Jeder der restlichen Triebe erzeugte im Durchschnitt 3,7 bis 4,7 Knollen. Weitere Verluste traten zwischen Ernte und Ploidie-Analysen von Pflanzen in der Knollenbildungs-Generation ein. Tabelle 2 gibt die durchschnittliche Zahl der Pflanzen, die in der Knollengeneration (überlebende Knollen) pro Trieb erzielt wurden. Tabelle 5 zeigt, dass 12,1% der Pflanzen in der Knollen-erzeugung in allen drei Keimschichten (LI Epidermis; LII Hypodermis; LIII innere Gewebe) verdoppelt waren. Dieser Verdopplungs-Prozentsatz lag wahrscheinlich tiefer als der von Ross et al. erreichte. Interaktionen zwischen den Klonen und der Triebregeneration werden den Erfolg der Methode in spezifischen F?llen stark beeinflussen. Analysen ergaben, dass Pflanzen von Knollen des gleichen Triebes ganz verschiedene Ploidie-Beschaffenheit haben k?nnen. W?hrend LI und LII oftmals in einer einzelnen Pflanze verschiedene Ploidie-Stufen aufwiesen, war die Ploidie-Stufe bei LII und LIII in 89,3% der F?lle gleich (Tabelle 3). Es wurde angenommen, dass dies den Beweis für die Theorie bekr?ftige, dass bei den Achselknospen LIII durch Zellen von LII, und umgekehrt, ersetzt werden kann. LI kam ?fters verdoppelt vor als LII (21,8% bzw. 12,8%), und bei in LI verdoppelten Pflanzen bestand die Neigung zur Verdoppelung auch in LII (Tabelle 4). Die praktischen Aspekte der Ploidie-Analysen wurden diskutiert, und es wurde geschlossen, dass für h?chste Leistungsf?higkeit, wenn immer m?glich, LII zuerst in Betracht gezogen werden sollte.

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Résumé Des données sont fournies pour quantifier l'efficacité d'une méthode de doublement végétatif (Dionne) chez la pomme de terre, méthode précédemment décrite par Ross et al. (1967). La méthode consiste dans le traitement à la colchicine (0,25% solution aqueuse de colchicine/48 h) des méristèmes nodaux sub-axillaires à la base des pseudostipules de scions de pomme de terre greffés sur des pieds enracinés de tomate. La tableau 1 montre qu'en moyenne 10,8 à 22% des méristèmes traités régénèrent de nouveaux bourgeons. Le chiffre le plus élevé est obtenu avec des clones libres de virus (B). Ce chiffre est assez semblable à celui obtenu par Ross et al. Il apparait de grandes différences clonales dans le taux de régénération. Le tableau 2 montre que de 31,8 à 51,3% des bourgeons ne produisent aucun tubercule après enracinement et plantation dans le sol. Ross et al. enrégistrent une perte de bourgeons du même ordre de grandeur. Les pertes sont principalement attribuées à la tardivité de la plantation au dehors de beaucoup de pousses, à la sur-dose de colchicine, et à un effet génotypique. Les bourgeons restants produisent chacun, en moyenne, 3,7 à 4,7 tubercules. Les pertes ultérieures apparaissent entre la récolte et l'analyse de la plo?die des plantes à la génération ‘tubercules’. Le tableau 2 montre le nombre moyen de plantes retenues à la génération ‘tubercules’ (tubercules survivants) par bourgeon. Le tableau 5 révèle que 12,1% des plantes de la génération ‘tubercules’ ont leur nombre chromosomique doublé dans toutes les trois premières couches du germe (LI épiderme; LII hypoderme; LIII tissu interne). Ce pourcentage de doublement est probablement inférieur à celui réalisé par Ross et al. On obtient un chiffre moyen de 0,5 de plantes entièrement doublées par greffe. Les interactions de régénération clone/bouture, etc. affecteront grandement le succès de la méthode dans des cas spécifiques. L'analyse a montré que des plantes provenant de tubercules d'une même bouture pouvaient avoir des constitutions plo?diques tout-à-fait différentes. Tandis que LI et LII ont fréquemment différents degrés de plo?die dans une même plante, LII et LIII sont les mêmes dans 89,3% des cas (tableau 3). Ceci est en faveur de la thèse selon laquelle les cellules de LII peuvent se substituer à LIII et vice versa aux bourgeons axillaires. LI est doublé plus fréquemment que LII (21,8 et 12,8% de doublement respectivement) et il apparait une tendance à ce que les plantes doublées en LI le soient également en LII (tableau 4). L'auteur discute des aspects pratiques de l'analyse plo?dique et conclut que, dans un but d'efficacité maximale, LII doit être analysé en premier lieu et aussit?t que possible.

     

籼型三系不育系泉5A的选育与特征特性

泉5A是福建省泉州市农业科学研究所以不育系V20A为细胞质供体,V41B／金23B的F2株系为细胞核供体,经多代回交选育而成的籼稻三系不育系,2007年通过福建省农作物品种审定委员会组织的鉴定。泉5A花粉败育彻底,育性稳定,不育株率与不育度均为100％;开花习性好,柱头外露率高,稻米品质较好,配合力强,达三系不育系利用的标准。     

Polycitorols A and B,New Tricyclic Alkaloids from an Ascidian

Two new tricyclic alkaloids, polycitorols A (1) and B (2) have been isolated along with the known lepadiformine (3) from a marine ascidian of the family Polycitoridae. The structures of the new compounds were elucidated by analysis of NMR data and comparison with those of 3 and other related compounds [1–5]. Compounds 1 and 2 are closely related to cylindricines A and B, lacking C-4 oxygenation found in cylindricines and having a butyl instead of a hexyl appendage. NOE experiments on compounds 1 and 2 suggested the A/B ring fusion to be cis.     

The importance of habitat resistance for movement decisions in the common lizard, Lacerta vivipara

ABSTRACT: BACKGROUND: Movement behaviour can be influenced by a multitude of biotic and abiotic factors. Here, we investigate the speed of movement in relation to environmental and individual phenotypic properties in subadult common lizards (Lacerta vivipara). We aim to disentangle the importance of substrate, cover, humidity, basking opportunity and individual phenotype on moving tendencies in 12 treatment combinations, at which each lizard was tested. RESULTS: We find that movement behaviour depends on the starting conditions, the physical properties of the dispersal corridor, and on the individuals' phenotype. Specifically, the presence of cover and substrate providing suitable traction in the corridor had positive effects on individual movement decisions. Additionally, we find high phenotypic variation in the propensity to move dependent on the presence of cover. Individual back patterns also strongly affected movement decisions in interaction with the physical properties of the dispersal corridor. CONCLUSIONS: Our results highlight the importance of understanding the habitat resistance for movement patterns, with humid habitats with covering vegetation providing the best conditions to initiate movement in the common lizard. In addition, population effects, differences in back pattern phenotype and individual plasticity were identified as key parameters influencing movement behaviour.     

A Review on Fucoidan Structure,Extraction Techniques,and Its Role as an Immunomodulatory Agent

Functional ingredients for human health have recently become the focus of research. One such potentially versatile therapeutic component is fucose-containing sulfated polysaccharides (FCSPs), referred to as fucoidans. The exploitation of marine brown algae provides a rich source of FCSPs because of their role as a structural component of the cell wall. Fucoidans are characterized by a sulfated fucose backbone. However, the structural characterization of FCSPs is impeded by their structural diversity, molecular weight, and complexity. The extraction and purification conditions significantly influence the yield and structural alterations. Inflammation is the preliminary response to potentially injurious inducements, and it is of the utmost importance for modulation in the proper direction. Improper manipulation and/or continuous stimuli could have detrimental effects in the long run. The web of immune responses mediated through multiple modulatory/cell signaling components can be addressed through functional ingredients, benefiting patients with no side effects. In this review, we attempted to address the involvement of FCSPs in the stimulation/downregulation of immune response cell signaling. The structural complexity and its foremost influential factor, extraction techniques, have also attracted attention, with concise details on the structural implications of bioactivity.     

印水型“三系”不育系中22A的选育与特征特性

本文总结了中22A的选育过程,检测了其在SSR标记上的特异性,并介绍了其特征特性及所配组合的产量表现。     

A 36 Mb terminal deletion of chromosome 2BL is responsible for a wheat semi-dwarf mutation

Reduced plant height is one of the most important traits related to lodging resistance and crop yield. The use of reduced height genes has been one of the main ...     

茶树良种无性系栽培及机械化采茶技术总结

由浙江省农业厅承担的农业部“茶树良种无性系栽培及机械化采茶技术”丰收计划项目，旨在通过无性系良种新技术的推广应用，促进茶叶生产进一步出效益、上台阶。该项目通过2000～2001年两年……     

A comparison of the ensilage, in an anaerobic cabinet, of grass, either fresh or when thawed after deep freezing

The suitability of freezing a large amount of grass from a single harvest for use in a series of experiments to investigate silage fermentation and its manipulation was examined. Perennial ryegrass, harvested in late June, was ensiled in sterile polythene bags inside an anaerobic cabinet; some was also stored frozen at -20°C for up to nine months before ensiling in a similar manner. The course of fermentation was followed using not only conventional chemical and microbiological analyses, but also by measuring microbial metabolic activity in vitro. Freezing and thawing affected the chemical composition and the microbial populations on the grass, and there were differences in the changes occurring in thawed grass during ensilage, probably related to damage to plant cells and impaired microbial activity associated with freezing and thawing. For both the grasses and the silages made from them, it was clear that the number of microorganisms present was not a reliable guide to microbial metabolic activity. Although the fermentation of frozen-and-thawed grass did not simulate precisely the fermentation occurring with fresh grass, it is concluded that, when used judiciously, the ensilage of thawed grass can be a useful experimental tool, particularly in the initial screening of manipulants of fermentation.     

在建设国际旅游岛背景下加快发展海南热带休闲农业的思路与对策

休闲农业是农业和服务业相结合的一种新兴休闲服务产业。海南建设国际旅游岛,加快海南农业现代化步伐,需要加快发展热带休闲农业。本文从海南发展热带休闲农业的必要性与可行性入手,分析制约其发展的诸多因素,提出加快发展海南热带休闲农业的思路与对策。     

Paralemnolide A, an Unprecedented Bisnorsesquiterpene from the Taiwanese Soft Coral Paralemnalia thyrsoides

Paralemnolide A (1), possessing an unprecedented bisnorsesquiterpene skeleton, was isolated from the soft coral Paralemnalia thyrsoides. The structure of paralemnolide A was elucidated by extensive analysis of spectroscopic data. The anti-HCMV (human cytomegalovirus) activity of 1 and its cytotoxicity against selected cell lines were evaluated.     

加快修购项目预算执行进度的思考——以中国热带农业科学院为例

以加快修购项目预算执行进度为切入点,介绍实施修购项目的重要意义,分析中国热带农业科学院(以下简称“热科院”)修购项目预算执行中存在的问题及原因,提出热科院加强修购项目预算执行进度管理的思路及办法。     

Taeanamides A and B,Nonribosomal Lipo-Decapeptides Isolated from an Intertidal-Mudflat-Derived Streptomyces sp.

Two new lipo-decapeptides, namely taeanamides A and B (1 and 2), were discovered from the Gram-positive bacterium Streptomyces sp. AMD43, which was isolated from a mudflat sample from Anmyeondo, Korea. The exact molecular masses of 1 and 2 were revealed by high-resolution mass spectrometry, and the planar structures of 1 and 2 were elucidated using NMR spectroscopy. The absolute configurations of 1 and 2 were determined using a combined analysis of ¹H-¹H coupling constants and ROESY correlations, the advanced Marfey’s method, and bioinformatics. The putative nonribosomal peptide synthetase pathway for the taeanamides was identified by analyzing the full genome sequence data of Streptomyces sp. AMD43. We also found that taeanamide A exhibited mild anti-tuberculosis bioactivity, whereas taeanamide B showed significant bioactivity against several cancer cell lines.     

DedA protein relates to action-mechanism of halicyclamine A, a marine spongean macrocyclic alkaloid, as an anti-dormant mycobacterial substance

A macrocyclic alkaloid, halicyclamine A, was re-discovered from an Indonesian marine sponge of Haliclona sp. 05A08 as an anti-dormant mycobacterial substance. To clarify action-mechanism of halicyclamine A, halicyclamine A-resistant strains were screened from the transformants of Mycobacterium smegmatis with the genomic DNA library of M. bovis BCG, which were constructed in the multi-copy shuttle cosmid pYUB145. Sequencing analysis of the cosmids isolated from the halicyclamine A-resistant transformants revealed that the responsible gene was involved in the genome region between 2920.549 kb and 2933.210 kb. Further experiments using the transformants over-expressing individual gene contained in the responsible region were executed, and the transformant, which over-expressed BCG2664 gene assigned as dedA gene, was found to become halicyclamine A-resistant. This evidence strongly suggested that DedA protein correlates with the action-mechanism of halicyclamine A as an anti-dormant mycobacterial substance.     

Stability and transferability assessment of the cotton fiber strength QTL qFS-c7-1 on chromosome A07

Previously we identified a major cotton fiber strength QTL(qFS-c7-1)on chromosome A07 using a multiparent advanced generation intercross(MAGIC)population.To assess the stability and transferability of this QTL and its utility in cotton breeding,we made ten new populations.These populations were developed from crosses between MAGIC recombinant inbred lines,or between cotton cultivars that are different from the MAGIC parents.A total of 2801 F₂ plants were grown and their fiber quality traits were measured.We also selected a subset of F₃ seeds from two populations,and grew F₃ progeny plots to further evaluate the stability of this QTL.Our results showed that the peak of qFS-c7-1 is at 70–72 Mb region.This QTL had a major effect on fiber strength explaining 21.9%phenotypic variance.Its effect on other fiber quality attributes such as micronaire,short fiber content,length and uniformity varied between populations,and no effect on fiber elongation was observed.The QTL effects were stable in the populations analyzed,and in different generations of the same population.The SSR and SNP markers near and within the QTL peak reported herein will assist selecting superior fiber quality traits in breeding,with a recommendation that the parental cotton lines should be analyzed using the seven DNA markers within the QTL peak before fully implementing marker assisted selection in a cotton breeding program.     

Identification and molecular characterization of novel LMW-m and -s glutenin genes,and a chimeric -m/-i glutenin gene in 1A chromosome of three diploid Triticum species

Low molecular weight glutenin subunits (LMWGs) are part of the gluten network that gives dough its viscoelastic properties. A-genome-containing diploid species related to modern polyploid wheat show great variability in these subunits. The current study characterized the variability of LMW-m and -s genes, being identified fifteen LMWGs genes in the three species evaluated, of which 14 were novel. Ten were pseudogenes, which are common in cereal prolamins. The rest of genes, with intact coding region, corresponded to the LMW-m genes and some single nucleotide polymorphisms and insertion/deletion events were detected, which could alter protein structure and affect dough quality. Two variants of the LMW-s genes were detected in cultivated einkorn and Triticum urartu, the former being novel. The LMW-m and -s genes were related to TuA3-391 and TuA3-400 genes, and to the Tu-460 gene, respectively, of T. urartu. Screening the sequences characterized for reactive epitopes of celiac disease revealed that LMW-m could be less toxic than other subunits for celiac patients. One novel chimeric gene with features from LMW-m and LMW-i genes was detected in T. urartu, and it produces a novel mature protein that may have a distinguishing effect on dough quality. Novel insights into the evolution of LMWGs genes are also reported. These species are a potential source of novel LMWGs variants.     

加快农业科技成果转化打造特色农业新优势

加速农业科技成果转化,提高生产水平,改进装备条件,是实现农业增效和农民增收的重要手段。近年来,盐城市通过实施国家农业科技成果转化资金项目,利用先进的技术成果推进农业产业化进程,农业综合生产能力明显增强。1农转资金项目概况自2001年设立国家农业科技成果转化资金项目以来,盐城市共承担了海水蔬菜的细胞及基因工程培育与海水栽培技术、优良栽培类型药用菊花有机生产主要配套技术中试与示范、水溶性水飞蓟素中试、优质家蚕新品种“苏豪钟晔”的中试与示范、杂交稻新品种及新型农机具在东盟(越南)示范应用等13个项目,项目涉及到动植物…