Histogenesis of the unique morphology of proboscidean ivory

The chequered pattern (often called Schreger pattern), which can be seen by unaided eye on transverse profiles of several proboscidean tusks and which can be emphasized by the spreading pattern of the cracks or by mineral discoloration, is an autapomorph feature of the clade Elephantoidea. The pattern differs among proboscidean taxa; therefore, it allows the coarse differentiation of elephants, mammoths, and some other basal groups. Such identification methods could facilitate efforts concerned with protection of the remaining elephant populations through ivory trade restrictions, since the tooth dentine from extinct Mammuthusprimigenius and from extant Loxodontaafricana and Elephasmaximus are the most common raw materials of the ivory carvings. The aim of this study was to show the internal structure of proboscidean ivory and to revise the existing theories on the aforementioned pattern of the elephantoids with reflections on the events which lead to the development of this microstructure. Thin sections and natural crack surfaces with various orientations of M.primigenius, Elephasantiquus, Prodeinotherium, and Deinotherium tusk fragments were used to produce a three‐dimensional model which explains the features on all profiles. The “phase shift” model is introduced, which assumes a sinusoid undulation of the dentinal tubules in radial profiles in the case of elephantoids. The model was confirmed by photomicrographs, scanning electron microscopic images, interpretation of natural crack surfaces, and radial displacement analysis of the dentinal tubules. The latter proved that the adjacent waves are not in the same phase. Several new nondestructive distinguishing methods are described here on the basis of the correlation between some microscopic and macroscopic features related to the Schreger pattern. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc.     

Module-based construction of plasmids for chromosomal integration of the fission yeast Schizosaccharomyces pombe

Integration of an external gene into a fission yeast chromosome is useful to investigate the effect of the gene product. An easy way to knock-in a gene construct is use of an integration plasmid, which can be targeted and inserted to a chromosome through homologous recombination. Despite the advantage of integration, construction of integration plasmids is energy- and time-consuming, because there is no systematic library of integration plasmids with various promoters, fluorescent protein tags, terminators and selection markers; therefore, researchers are often forced to make appropriate ones through multiple rounds of cloning procedures. Here, we establish materials and methods to easily construct integration plasmids. We introduce a convenient cloning system based on Golden Gate DNA shuffling, which enables the connection of multiple DNA fragments at once: any kind of promoters and terminators, the gene of interest, in combination with any fluorescent protein tag genes and any selection markers. Each of those DNA fragments, called a ‘module’, can be tandemly ligated in the order we desire in a single reaction, which yields a circular plasmid in a one-step manner. The resulting plasmids can be integrated through standard methods for transformation. Thus, these materials and methods help easy construction of knock-in strains, and this will further increase the value of fission yeast as a model organism.     

Twopictonia (perisphinctidae) from the subbetic upper jurassic of spain

Two ammonites belonging to the genusPictonia Bayle, 1878 (subgenusPachypictonia Schneid, 1940) are described from the Lower Kimmeridgian of the Subbetic of Western Andalusia, this being the first evidence of the presence of this genus in the Mediterranean (Tethydian) Upper Jurassic.     

Phospholipidgranula im verhornenden Oesophagusepithel

Zusammenfassung Im Epithel des Meerschweinchenoesophagus fanden wir mit Ausnahme des Stratum corneum in jeder Schicht 0,1–0,3 große, lamellär-strukturierte Granula. Die Granula werden meistens von einer Membran (unit-membrane) umgeben, die ein lamelläres System in sich einschließt, das eine Periodizität von 60–70 Å aufweist und aus dunklen und hellen Lamellen besteht. Unsere Annahme, daß die Granula Phospholipide enthalten, wird durch die Beobachtung unterstützt, daß die Lokalisation der lichtmikroskopisch durchgeführten Baker-Reaktion vollkommen mit der Verteilung der lamellären Granula im elektronenmikroskopischen Bild übereinstimmt. Nach Pyridinextraktion ist die Baker-Reaktion negativ, während im elektronenmikroskopischen Material an Stelle der Granula nur Vakuolen zu finden sind.Die Granula erscheinen im Stratum germinativum meistens in Verbindung mit dem Golgiapparat und entleeren sich in Höhe des Stratum granulosum in den interzellulären Raum. Zwischen den Lamellen des Stratum corneum ist das Material der Granula als eine homogene, dunkle, amorphe Deckschicht vorhanden. Ihre Aufgabe besteht wahrscheinlich in der Steigerung der Resistenz der Hornschicht.

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Summary Lamellated granules of 0,1 to 0,3 in diameter are consistently found in all strata of the keratinizing epithelium of the guinea pig oesophagus. The granules are surrounded by a single membrane (unit membrane) and contain a lamellated system consisting of dark and light bands showing a periodicity of 60 to 70 Å. The supposed phospholipid nature of the granules was supported by the positive Baker-reaction at the light microscope level. The distribution of the Baker-positive substance was identical with that of the lamellated granules at the electron micrograph. After extraction with pyridin, the Baker-reaction turned out to be negative while on the electron micrographs the substance of the lamellated granules was lost.The granules first appear near the Golgi region of the stratum germinativum and are emptied into the extra-cellular space at the level of the stratum granulosum. The substance of the granules, after having lost their lamellated structure, remains between the keratinized layers as a homogenous, dense material. Its function probably consists in increasing the resistance of the cornified layer against chemical agents.

     

Preparation of anti-inhibitor serum and its effect on the multiplication of influenza virus

Antiserum был подготовлен противингибитор вируса haemagglutination (IVH)одна из эмбриона chorioallantoic мембр анныепутем иммун изации морских св инокЭто анти-инги битора в сыворотке заблокирован ингибирование IVH из chorioallantoicмембран в haemagglutination испытанияно ника кого влияния на ре цепторы эритроци товСыворотке кро] ви не влияет рост chorioallantoic мембраны клет ок инет нейтрализ овать воздействи е на вирус гриппа Она снизилась спо собность chorioallantoic мембр ан для adsorb вируса гри ппа, а также степен ь размножения вир усав такого рода тканиАвторы хоте ли бы поблагодари ть г-н Г. Ruttkay-Ne -палубе и для проведения эле ктрофореза меру ния.     

Prerequisite for His4 in deltorphin A for highδ opioid receptor selectivity

Summary Analysis of deltorphin A position 4 analogues included: backbone constrained N MeHis, spinacine (Spi), N MePhe and the tetrahydroisoquinoline-3-carboxylic acid (Tic); spatially confined side-chain (Phg); and imidazole alkylation ofl- andd-His⁴ enantiomers. High selectivity was lost with the following replacements: N MeHis⁴, N MePhe⁴ and Phg⁴ reduced binding and the constrained residues also increasedµ binding; ring closure between the side-chain and amino group to yield Spi⁴ or Tic⁴ increasedµ affinity. Imidazole methylation of His⁴ marginally affected opioid binding and doubled selectivity; alkylatedd-His⁴-derivatives generally maintained selectivity in spite of decreased affinities. Thus, His⁴ imidazole preserves selectivity by facilitating high binding and by repulsion at theµ receptor. Several low energy conformers of deltorphin A indicated that the His⁴ imidazole preferred a spatial orientation parallel to the phenolic side-chain of Tyr¹ suggestive that this conformation might contribute to high affinity and selectivity.