Transient gene expression in shoot apical meristems of sugarbeet seedlings after particle bombardment

Sugarbeet apices were used as targets for particle bombardmentwith a microtargeting device. Before examining gene expression,particle penetration experiments were carried out. TransientGUS expression was detected within the first and second celllayers of the meristem. Dividing cells with GUS activity demonstratedthat cells survived the bombardment procedure. Key words: Beta vulgaris, direct gene transfer, microtargeting, particle bombardment, shoot apical meristem     

Morphology and proliferation kinetics of early tumor stages induced by dimethylnitrosamine in rat kidneys

A total of 49 dimethylnitrosamine (DMN)induced rat renal cell tumors were analyzed and classified cytomorphologically at an early stage of development. Of these, 17 were basophilictubular tumors, two of which showed a direct transition to proximal tubules of the P₃segment; 21 lesions were vacuolated and contained glycogen; these were defined cytomorphologically as a separate tumor type the histogenetic derivation of which from the collecting duct system was established by documentation of a direct transition. Morphological similarities point to the lipidstoring variant of the basophilic tumor, but a carcinoma of the ducts of Bellini is another possible human equivalent of this tumor type. Another seven lesions were clear and granular cell tumors. In two of these a direct transition from the collecting duct system was found, thus confirming that this only recently established origin of experimentally induced rat renal clear cell tumors also applies to lesions induced by DMN. The proliferation kinetics of DMNinduced lesions were studied in autoradiograms after pulselabeling with tritiated thymidine. The basal proliferation of these early tumor stages displayed a marked proliferative advantage over the normal parenchyma. The lesions were still subject to physiological growth stimulation as determined by³HTdRcontinuouslabeling with osmotic minipumps following unilateral nephrectomy. However, compared with normal kidney parenchyma, the³HTdRlabeling index of the lesions was even higher indicating a response modification during early neoplasia.     

Applied microfacies analysis: Provenance studies of Roman mosaic stones

Summary Provenance analysis of archaeological materials is an essential tool of archaeometry but has been rarely applied to antique mosaics. Many mosaics are made of carbonate mosaic stones (tesserae). Hence, microfacies analysis offers a great potential in differentiating these limestone tesserae and provenancing their local, regional, imported or recycled origins. The methods of microfacies analysis and their prospects for studying mosaics are demonstrated by case studies of Roman mosaics from southern Germany (Kraiburg, Bavaria). Austria (Hemmaberg near Globasnitz, southern Carinthia), Italy (Asolo north of Padova) and late Punic and Roman mosaics from Tunisia (Carthage and Hergla). Microfacies-based provenance analysis comprises six stages: 1) Macroscopic assessment and definition of rock colour groups of tesserae, 2) Sampling based on rock-colour categories, 3) Definition of microfacies types and attribution to standard microfacies types based on thin-section criteria, 4) Evaluation of the mosaic site with respect to geological and paleontological data followed by comparisons of the microfacies inventory of the region with microfacies types of the tesserae, 5) Assessment of carbonate tesserae to specific geological rock/time units followed by suggestions of provenance sites. 6) Critical evaluation of provenance assessment within the archaeological context. Principal limestone colours do not necessarily coincide with specific limestone types. Uniformly coloured tesserae can represent different limestone types from different sources (cf. Kraiburg, Hemmaberg). On the other hand, a specific limestone type may be characterized by different rock colours (cf. Carthage). Provenance assessment of mosaic stones results in relatively narrow (Hemmaberg, Asolo) or only broad (Carthage, Hergla) indications of sites characterized by exposures of carbonate rocks whose microfacies criteria, geological age and rock colour correspond to those of the carbonate tesserae. The case studies argue for local and/or imported (Kraiburg) as well as regional provenances of the mosaic material (Hemmaberg, Asolo; source area within a distance between 10 and about 40 km) and indicate that off-cuts of building stones exploited within a regional frame might possibly have been used (Carthage). Differences in the composition and diversity of carbonate rocks used for the fabrication of mosaics reflect time-dependent changes in major quarrying and potential source areas (Carthage). Further provenance research of mosaics should be based on statistically representative tesserae samples, supplemented by microfacies studies of the building material used at the mosaic sites as well as investigation of nonlithic tesserae and the mortar bedding of the mosaics. The isotopic composition of limestone and dolomite tesserae also assists in the critical evaluation of microfacies categorization.     

Influence of Age on the Rhythm in Basal and Forskolin-Stimulated Adenylate Cyclase Activity of the Rat Heart

-In male rats of three different ages (Group 1:7 weeks, Group II: 4 months, Group III: ≥ 10 months) basal and forskolin-stimulated adenylate cyclase (AC) activity were investigated in rat heart ventricles of animals sacrificed at 8 time points within 24 hours of a day. Maximum (Emax) and half-maximum (EC50) stimulation by a water-soluble forskolin (FOR; 0.1-100 μmol/l) were determined from dose-response curves. In young rats (Group I) significant rhythmicity was found in basal and FOR-stimulated AC activity, which was successively reduced or abolished with age by a reduction in amplitude. Mean basal AC activity increased about 2-fold from Group I to Group II/III. Mean maximum in for stimulation was about 12-fold in Group I and about 7-fold in Group II and ID. EC50-values displayed neither a significant rhythmicity in either group nor an age-dependency. It is concluded that the stimulatory potency of the catalytic subunit of the AC is reduced with age.     

Numerical flow simulation of pool-type fishways: new ways with well-known tools

Fish passage structures are built to restore the connectivity of rivers and allow the migration of aquatic fauna. In order to assess the functioning of a pool-type fishway, it is necessary, inter alia, to possess detailed knowledge of its flow structure, since observations of fishways, and in particular of the visible water surface, can only provide a rough idea of the actual conditions inside the pools. Numerical simulation has been used for many years to support engineering sciences. Especially, the modeling of flow processes in hydraulic machines can, on the one hand, help avoid major problems during the design stage of fish passage structures and, on the other, improve the structure’s hydraulic performance. To this end, two diploma theses within the framework of a research project of the local energy supplier Energie Baden-Württemberg AG (EnBW) employed modeling tools for 3D flow simulation, primarily for pool-slot fishways (PSF), and for traditional vertical slot fishways (VSF). Guest editors: R. L. Welcomme & G. Marmulla Hydropower, Flood Control and Water Abstraction: Implications for Fish and Fisheries     

A specific and sensitive double-immunofluorescence method for the demonstration of S-antigen and serotonin in trout and rat pinealocytes by means of primary antibodies from the same donor species

 Immunocytochemical double-labeling methods are important tools in cell and neurobiology. Here we describe a method which is based on double immunofluorescence and allows specific detection of two different antigens located in the same cell compartment by two primary antibodies raised in the same species. As an example, we present the double-immunolabeling method for the S-antigen (SAg), a photoreceptor-specific protein, and the indoleamine serotonin (5HT) in dissociated trout and rat pineal cells immobilized on coversliped and in frozen sections of the trout pineal organ. As a first step, the preparations on the slides or coverslips were sequentially incubated with the first primary antibody (rabbit anti-SAg), the fluorescein-labeled (anti-rabbit) secondary antibody, and then with normal rabbit serum. Meanwhile, the second primary antibody (rabbit anti-5HT) was coupled to a Cy3-labeled secondary (anti-rabbit) antibody in a reaction tube and excess binding sites were quenched with normal rabbit serum. This complex was applied to the specimens after completion of the first (SAg) immunoreaction on the slide. For control experiments, the first (anti-SAg) or the second (anti-5HT) primary antibody were omitted. Most of the rat and trout pinealocytes were double immunolabeled for SAg and 5HT. In the trout, few cells contained SAg or 5HT immunoreaction only. This underlines the selectivity of each immunoreaction. The results show that the method can be used for the analysis of whole cells and tissue sections by means of conventional fluorescence and confocal laser scanning microscopy. Accepted: 20 October 1997     

Transient gene expression in vegetative shoot apical meristems of wheat after ballistic microtargeting

A method has been established that allows the targeted delivery of DNA-carrying gold particles to vegetative shoot apical meristems of cereal species. Meristems of 8- to 10-day-old seedlings of wheat ( Triticum aestivum ), rice ( Oryza sativa ) and sorghum ( Sorghum bicolor ) were manually exposed by removal of the coleoptile and the first three to four leaves. Using ballistic microtargeting, equal-sized gold particles of different diameters ranging from 1.0 to 2.0 µm were propelled to meristems by pulses of compressed nitrogen ranging from 9 to 13 MPa. When accelerated by 13 MPa, particles of 1.4 µm or larger penetrated to cells of L2 in 80% of the bombarded wheat meristems. Expression vectors containing either the gene for β-glucuronidase ( gusA ) or genes regulating the anthocyanin biosynthesis ( Bperu and C1 from maize) were delivered to wheat meristems. The level of transient gene expression was dependent on the osmotic pressure of the MS-based medium that was used to mount the explants for shooting: an increase of the sucrose concentration from 2 to 10% in the medium resulted in an increase of transient gene expression from 5 to 25% of the bombarded meristems. Although particles of 1.4 µm were efficiently delivered to L1 and L2, transient gene expression occurred predominantly in the L1 layer. In contrast, up to 10% of the bombarded meristems had expressing cells in L2 when particles of 2.0 µm were used. Ten days after bombardment, GUS-positive sectors in meristems and in leaf primordia were observed. When destructive GUS detection was omitted, between 80 and 90% of the bombarded ex-plants recovered in vitro on basal MS medium and then regenerated to fertile plants in the greenhouse.     

PI5P4Ks drive metabolic homeostasis through peroxisome-mitochondria interplay

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