Floral synorganization and its influence on mechanical isolation and autogamy in Marantaceae

The flowers of Marantaceae (～ 550 species) exhibit a highly derived pollination mechanism within Zingiberales, with a rapid and irreversible style movement based on a close synorganization of different floral parts. Given the complexity of the structure, we assume that little variation is possible if functionality is to be maintained. To test this, we investigated how much floral diversity exists in the clade and whether this diversity potentially influences the breeding system and placement of pollen on the pollinator. Flowers of 66 species covering the five major phylogenetic clades of the family were analysed. All species are similar in their basic flower construction: the fleshy staminode forms the tunnel‐shaped roof of the flower and narrows the tube with stiff swellings, and the hooded staminode holds the style under tension and narrows the flower entrance with its trigger appendage. Despite morphological diversity of the pollination apparatus, functionality is maintained by coordinated variation of the fleshy and hooded staminodes. Autogamy is usually avoided by herkogamy. However, in a few exceptions, subtle morphological changes alter the breeding system from allogamy to autogamy. Variable floral proportions allow for differential pollen deposition potentially causing mechanical isolation between sister taxa. This study clearly illustrates that structural variation is not only present in the highly synorganized flowers of Marantaceae, but that it also creates potentially new options for evolutionary diversification. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168 , 300–322.     

2-Styrylindolium based fluorescent probes visualize neurofibrillary tangles in Alzheimer’s disease

We evaluated 2-styrylindolium derivatives (6–11) as novel and selective probes for neurofibrillary tangles (NFTs) on brain sections of AD patients. The staining experiments indicated that these compounds may bind selectively to NFTs in the presence of ß-amyloid (Aß) plaques. Cell free binding assays confirmed that 2-[2-[4-(1-pyrrolidinyl)phenyl]ethenyl]-1,3,3-trimethyl-3H-indolium iodide (9) and 2-[2-[4-(diethylamino)phenyl]ethenyl]-1-butyl-3,3-dimethyl-3H-indolium iodide (11) display excellent affinities to Tau-aggregates (IC₅₀ values of 5.1 and 1.4 nM, respectively) in the displacement of Thiazin Red R. These probes have good solubility in distilled water and low or no cytotoxicity in zebrafish embryo and liver hepatocellular carcinoma cell assays.     

An alginate-layer technique for culture of Brassica oleracea L. protoplasts

Ten accessions belonging to the Brassica oleracea subspecies alba and rubra, and to B. oleracea var. sabauda were used in this study. Protoplasts were isolated from leaves and hypocotyls of in vitro grown plants. The influence of selected factors on the yield, viability, and mitotic activity of protoplasts immobilized in calcium alginate layers was investigated. The efficiency of protoplast isolation from hypocotyls was lower (0.7 ± 0.1 × 10⁶ ml⁻¹) than for protoplasts isolated from leaf mesophyll tissue (2 ± 0.1 × 10⁶ ml⁻¹). High (70–90%) viabilities of immobilized protoplasts were recorded, independent of the explant sources. The highest proportion of protoplasts undergoing divisions was noted for cv. Reball F1, both from mesophyll (29.8 ± 2.2%) and hypocotyl (17.5 ± 0.3%) tissues. Developed colonies of callus tissue were subjected to regeneration and as a result plants from six accessions were obtained.     

The morphology and evolution of the female postabdomen of Holometabola (Insecta)

In the present article homology issues, character evolution and phylogenetic implications related to the female postabdomen of the holometabolan insects are discussed, based on an earlier analysis of a comprehensive morphological data set. Hymenoptera, the sistergroup of the remaining Holometabola, are the only group where the females have retained a fully developed primary ovipositor of the lepismatid type. There are no characters of the female abdomen supporting a clade Coleopterida + Neuropterida. The invagination of the terminal segments is an autapomorphy of Coleoptera. The ovipositor is substantially modified in Raphidioptera and distinctly reduced in Megaloptera and Neuroptera. The entire female abdomen is extremely simplified in Strepsiptera. The postabdomen is tapering posteriorly in Mecopterida and retractile in a telescopic manner (oviscapt). The paired ventral sclerites of segments VIII and IX are preserved, but valvifers and valvulae are not distinguishable. In Amphiesmenoptera sclerotizations derived from the ventral appendages VIII are fused ventromedially, forming a solid plate, and the appendages IX are reduced. The terminal segments are fused and form a terminal unit which bears the genital opening subapically. The presence of two pairs of apophyses and the related protraction of the terminal unit by muscle force are additional autapomorphies, as is the fusion of the rectum with the posterior part of the genital chamber (cloaca). Antliophora are supported by the presence of a transverse muscle between the ventral sclerites of segment VIII. Secondary egg laying tubes have evolved independently within Boreidae (absent in Caurinus) and in Tipulomorpha. The loss of two muscle associated with the genital chamber are likely autapomorphies of Diptera. The secondary loss of the telescopic retractability of the postabdomen is one of many autapomorphies of Siphonaptera.     

Epidemiological association of Campylobacter jejuni groups with pathogenicity-associated genetic markers

ABSTRACT: BACKGROUND: Campylobacter jejuni, the most leading cause for bacterial gastroenteritis worldwide, shows a high genetic diversity among its isolates. Recently, we demonstrated the existence of six C. jejuni-groups by combining MLST with six genetic markers. These groups were further characterized by the detection of cj1321-cj1326, fucP, cj0178, cj0755/cfrA, ceuE, pldA, cstII, and cstIII in order (I.) to show further associations between these different genetic markers and MLST CCs. Moreover, different studies were able to associate several of these markers: a sialylated lipoologosaccharide (cstII/III+), the gamma-glytamyl-transpeptidase (ggt+), and the absence of a certain allele of the enterochelin-uptake-binding-protein (ceuE11168-) with severe campylobacteriosis, bloody diarrhea and unpleasant outcome. Additionally more than half of human Campylobacter-isolates were assigned to a non-livestock clade associated with the absence of cj1321-cj1326. These isolates were considered as mere colonizers. From the combination of marker genes, the ratio of human isolates in a specific group, and clinical data (II.) it should be demonstrated to which of the previous defined groups these Campylobacter-subpopulations, associated with higher virulence, correspond. RESULTS: Besides the marker gene pldA, all new estimated genetic markers show significant differences in their distribution among the various MLST-based groups. Especially the genes for cj1321-cj1326, fucP, cj0178, cj0755/cfrA are widely associated with each other and split the study population into two major and seven intermediate groups substantiating the previous group-definition, whereas cstII and cstIII indicate at least three groups following an independent distribution pattern. CONCLUSIONS: Based on these data a group of C. jejuni-isolates characterized by the presence of ansB, dmsA, ggt, and the absence of cj1365c, cj1585c, cj1321-cj1326, fucP, cj0178, cj0755/cfrA, and cstII/III was associated with a higher prevalence in human campylobacteriosis, bloody diarrhea as well as hospitalization and bears obviously a higher virulence for humans. In contrast to that better livestock-adapted groups characterized by the ability to utilize L-fucose and the presence of all of the ve identied putative C. jejuni iron-uptake systems as well as cj1321-cj1326, cj1365c, cj1585c, and cstII and/or cstIII (sialylated lipoologosaccharide) is more prevalent in animal hosts and was secondary associated with less severe campylobacteriosis.     

不同老化程度的不结球白菜种子活力指标变化及其相关分析

以不结球白菜品种‘高梗白’种子为材料,采用高温(42℃)高湿(相对湿度100%)人工加速老化处理,研究不同老化程度下种子活力指标的变化及其相关性。结果显示:(1)发芽指标(除不正常苗率)和出苗指标均随种子老化程度的加深而显著下降,不正常苗率显著上升。(2)随老化程度的加深,种子中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性显著下降;种子的超氧阴离子(O2.-)产生速率先增高后降低,过氧化氢(H2O2)含量逐渐增加,丙二醛(MDA)含量下降,种子浸出液相对电导率升高;种子的可溶性糖含量、可溶性蛋白含量和脱氢酶活性下降,α-淀粉酶活性先升高后降低。(3)老化种子的发芽势、发芽率、SOD活性、H2O2含量、相对电导率和可溶性糖含量与出苗指标间均存在极显著相关性。研究表明,不结球白菜种子的发芽势、发芽率、SOD活性、H2O2含量和可溶性糖含量随老化程度加深的变化规律一致,且指标间以及与出苗指标均有极显著相关性,可以作为检验不结球白菜种子活力的候选指标。     

中国野生毛葡萄芪合成酶基因克隆及表达分析

采用RT-PCR技术克隆中国野生毛葡萄‘丹凤-2’芪合成酶基因,命名为VqDSTS1,并进行序列及表达模式分析.结果表明:VqDSTS1基因cDNA编码区全长为1 179bp,GenBank登录号为JQ342086,编码392个氨基酸;氨基酸序列分析表明,VqDSTS1含有芪合成酶基因家簇的特征识别序列‘IPNSAGAIAGN’和‘GVLFGFG-PGLT’;序列比对显示,VqDSTS1与其他葡萄种质的芪合成酶氨基酸序列一致性在95.2%～98.7%之间;半定量RT-PCR分析表明,VqDSTS1受白粉病诱导表达,呈双峰模式.为进一步研究中国野生毛葡萄‘丹凤-2’芪合成酶基因家族的表达及功能分析提供了基础.     

水稻NHX1基因启动子和C末端的调控功能研究

为了解水稻Na+/H+逆向转运蛋白(OsNHX1)在植物应答非生物胁迫中的分子调控机制,采用RT-PCR方法克隆OsNHX1基因上游2 000bp的启动子序列,并通过基因枪轰击瞬时转化洋葱表皮细胞,检测不同非生物胁迫下启动子的活性和表达模式;同时,分别克隆全长和C末端缺失的OsNHX1基因,通过花序浸染法转化拟南芥,研究OsNHX1基因及其C末端的功能。结果显示:OsNHX1启动子受逆境胁迫诱导,在盐、干旱、脱落酸胁迫处理下GUS表达活性明显升高;过表达OsNHX1的转基因拟南芥中,种子萌发率、根长、丙二醛含量和相对含水量的测定结果均显示其胁迫耐受性得到改善,但过表达OsNHX1C末端缺失基因对转基因植株的胁迫耐受性无明显影响。研究表明,Na+/H+逆向转运蛋白有助于提高植物耐盐性,且其C末端区域对该转运蛋白活性的发挥具有关键作用。     

Synthesis and SAR-study for novel arylpiperazine derivatives of 5-arylidenehydantoin with α₁-adrenoceptor antagonistic properties

The study is focused on a series of 5-arylidenehydantoin derivatives with a phenylpiperazine-hydroxypropyl fragment at N3 of the hydantoin ring. The compounds were assessed on their affinity for α(1)-adrenoceptors and evaluated in functional bioassays for their antagonistic properties. Crystal structures of (Z)-5-(4-chlorobenzylidene)-3-(3-(4-(2-ethoxyphenyl)piperazin-1-yl)-2-hydroxypropyl)imidazolidine-2,4-dione (7) and hydrochloride of (Z)-5-(4-chlorobenzylidene)-3-(2-hydroxy-3-(4-(2-methoxyphenyl)piperazin-1-yl)propyl)imidazolidine-2,4-dione (10a) were solved using the X-ray diffraction method. Classical molecular mechanics (MMFFs force field, MCMM, MacroModel) were used to predict 3D structure of compounds 5a-18a using a crystal structure of 7. SAR analysis was performed on the basis of Barbaro's pharmacophore model and structural properties of previously investigated α(1)-adrenoceptor antagonists possessing a hydantoin fragment. Most of the compounds exhibited significant affinities for α(1)-ARs in nanomolar range (40-290 nM). The highest activities (K(i)<75 nM) were observed for compounds possessing a 2-alkoxyphenylpiperazine fragment and two methoxy substituents at the benzylidene moiety. The results indicated that chemical properties, number and positions of substituents at the 5-arylidene fragment influenced the power of α(1)-affinities as follows: 3,4-di CH(3)O>2,4-di CH(3)O>4-Cl>2,3-di CH(3)O>H>4-N(CH(3))(2).     

Physiological implications of pair-bond status in greylag geese

In group-living vertebrates, reliable social allies play a decisive role in dealing with stressors. For example, support by social allies is known to dampen glucocorticoid responses. It remains unknown, however, how social embedding affects the sympatho-adrenergic axis as indicated by heart rate (HR) in non-human animals. We studied the relationships between HR, pair-bond status and distance from the pair-partner in twenty-five free-ranging greylag geese (Anser anser) in a natural social environment. In three individuals, we investigated HR responses following partner loss. Overall, we found a context- and sex-dependent difference in HR between paired and unpaired individuals, paired males having a lower HR during agonistic encounters, and unpaired females having a lower HR during resting. Also, in paired females HR increased with increasing distance from the partner. Our data suggest that HR is modulated by pair-bond status in greylag geese in a context- and sex-dependent manner, which may be representative for social vertebrates in general. Despite the low sample size, the present study indicates that proper social embedding may optimize an individual's physiological investment in the social domain. This reduces individual energy expenditure and may benefit health and reproductive success.