Über das gleichzeitige Vorkommen von zweierlei Eiweißkörpern in den Zellkernen vonPseudolysimachion spicatum und einigen anderen Scrophulariaceen

Zusammenfassung Die Zellkerne vonPseudolysimachion spicatum, Veronica cymbalaria undV. gentianoides enthalten zweierlei Eiweißkörper von je nach dem Entwicklungszustand unterschiedlicher Konsistenz. Bis zum Höhepunkt ihrer Entwicklung liegen sie als anscheinend amorphe flüssige oder gelartige Gebilde vor. Später tritt — mit gewebespezifischen Unterschieden — Verfestigung und Kristallisation ein, und zwar bei beiden nicht gleichzeitig und z. T. auch nur beim großen. Beiderlei Körper unterscheiden sich deutlich in physikalischer und chemischer Hinsicht, außerdem in ihrer Entwicklungsgeschichte und Strukturveränderung. Sie fehlen in den Schließzellen, im Antherentapetum, in den Pollenmutterzellen, Pollenkörnern, im Embryosack, im Endosperm und im Embryo.Die Zellkerne in der Blattepidermis vonPenstemon barbatus enthalten ebenfalls zweierlei Eiweißkörper. Davon liegt einer als kugeliges Gebilde, der andere als Kristallstapel vor.

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Summary In the nuclei ofPseudolysimachion spicatum, Veronica cymbalaria, V. gentianoides there occur two different kinds of protein bodies. They clearly differ from one another in physical and chemical regard as well as in their ontogeny. At first they are amorphous, liquid or geluous. As a rule a consolidation or crystallization with differences according to the tissue takes place after the climax of the development, and that not at the same time within both bodies. In the stomata cells, pollen mother cells, in the embryo sac, in the endosperm, in the endothelium and in the embryo both bodies do not occur.The nuclei in the epidermis of the leaves ofPenstemon barbatus also contain two different kinds of protein bodies, one of them appearing as a round body, and the other one as a pile of crystal plates.

     

Über Struktur und Innervation der quergestreiften Muskulatur des Oesophagus der Ratte

Zusammenfassung Die Muskelwand des Rattenoesophagus besteht ausschließlich aus quergestreiften Muskelfasern. Diese weisen keine Strukturunterschiede gegenüber gewöhnlichen Skeletmuskeln der Ratte auf. Sie sind in zwei spiralig gegenläufigen Muskelschichten angeordnet. Zwischen den beiden Muskelschichten befindet sich ein mit ChE-Darstellungsmethoden anfärbbarer Plexus myentericus, der an seinen Kreuzungspunkten regelmäßig Ganglienzellen aufweist. 10% der Ganglienzellen sind stark ChE-positiv, es handelt sich um tiberwiegend spezifische AChE.Die Rr. oesophagei des N. vagus zeigen sowohl marklose als auch myelinisierte Axone. Die Endäste, die den Plexus verlassen, um an motorischen Endplatten zu endigen, sind marklos.Die motorischen Endplatten weisen muldenförmige Einsenkungen des Sarkolemms auf. Die subsynaptische Membran ist reichlich in Palten gelegt, auch dort, wo ihr kein terminales Axon aufliegt. Es wurden 2 Arten von terminalen Axonen an den Endplatten festgestellt: 1.Dicke Axone, die mit vielen synaptischen Bläschen angefüllt sind, daneben aber auch einige granulierte Bläschen enthalten. 2. Dünne, fast ausschließlich mit granulierten Bläschen erfüllte Axone. Oft berühren die terminalen Axone einander unmittelbar, bisweilen unter Bildung von Membranverdickungen.

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Structure and innervation of the striated muscle fibres of the esophagus of the rat

Summary The muscular wall of the esophagus of the rat consists exclusively of striated muscle fibers which do not differ from the skeletal muscles of the same animal. These fibres are arranged in two layers running spirally in contrary directions. Between these two layers a ChE-positive myenteric plexus occurs, containing several ganglionic cells at its crossing points. 10 per cent of these ganglionic cells are strongly AChE-positive. The tiny branches of the vagus nerve, passing through the outer muscular layer into the myenteric plexus consist of bundles of unmyelinated as well as myelinated fibres. The terminal branches of the plexus leading to motor endplates are unmyelinated.The motor endplates are situated in trough-shaped impressions of the surface of muscle fibres. The subsynaptic sarcolemma is richly folded, even in places where there is no overlying synaptic terminal.There are two kinds of nerve terminals in the motor endplates: (1) Thick terminals abundantly filled with clear synaptic vesicles but also containing a few dense core vesicles. (2) Thin axons containing predominantly granulated vesicles.The synaptic nerve terminals often come into contact with each other, occasionally forming membrane thickenings at such places.

     

Extensive changes in cytokeratin expression patterns in pathologically affected human gingiva

The stratified squamous epithelium of the oral gingiva and the hard palate is characterized by a tissue architecture and a cytoskeletal composition similar to, although not identical with, that of the epidermis and fundamentally different from that of the adjacent non-masticatory oral mucosa. Using immunocytochemistry with antibodies specific for individual cytokeratins, in situ hybridization and Northern blots of RNA with riboprobes specific for individual cytokeratin mRNAs, and gel electrophoresis of cytoskeletal proteins of microdissected biopsy tissue samples, we show changes in the pattern of expression of cytokeratins and their corresponding mRNAs in pathologically altered oral gingiva. Besides a frequently, although not consistently, observed increase in the number of cells producing cytokeratins 4 and 13 (which are normally found as abundant components in the sulcular epithelium and the alveolar mucosa but not in the oral gingiva) and a reduction in the number of cells producing cytokeratins 1, 10 and 11, the most extensive change was noted for cytokeratin 19, a frequent cytokeratin in diverse one-layered and complex epithelia. While in normal oral gingiva cytokeratin 19 is restricted to certain, sparsely scattered cells of --or near--the basal cell layer, probably neuroendocrine (Merkel) cells, in altered tissue of inflamed samples it can appear in larger regions of the basal cell layer(s) and, in apparently more advanced stages, also in a variable number of suprabasal cells. Specifically, our in situ hybridization experiments show that this altered suprabasal cytokeratin 19 expression is more extended at the mRNA than at the protein level, indicating that cytokeratin 19 mRNA synthesis may be a relatively early event during the alteration. These changes in cytokeratin expression under an external pathological influence are discussed in relation to other factors known to contribute to the expression of certain cytokeratins and with respect to changes occurring during dysplasia and malignant transformation of oral epithelia.     

Diffusible IAA and dominance phenomena in fruits of apple and tomato

The relationships between indole-3-acetic acid (IAA) diffusing out of the fruit and competition among fruits, and between fruits and shoot tips were investigated using apple ( Malus domestica Borkh. cv. Jonagold) and tomato ( Lycopersicon esculentum Mill.) plants. Dominant fruits always had more diffusible IAA than subordinated, inhibited fruits. Alterations in dominance – by fruit- or shoot tip removal – led to significant changes in diffusible IAA by the remaining fruits. This change could be detected one day after dominance modification.
It is suggested that diffusible IAA is involved in the correlative signal regulating dominance relationship between fruits, and between fruits and shoots in apple and tomato.     

Interaction of nuclear factors with upstream sequences of a lipid body membrane protein gene from carrot.

To study the regulation of gene expression during embryo development, we isolated a gene, DC 59, expressed in embryos but not in mature carrot plants. Sequence and S1 analysis showed that the gene was composed of one exon encoding a polypeptide of 19 kilodaltons and was highly homologous to the lipid body membrane protein gene L3 from maize. The plant hormone abscisic acid regulated the accumulation of DC 59 mRNA. To understand the mechanism of embryo-specific and hormonal regulation of DC 59, 5' DNA fragments were incubated with nuclear proteins. Two adjacent regions (from -706 to -235) interacted with nuclear extracts from embryos, resulting in the formation of four complexes (C1, C2, C3, and C4). Factors involved in the formation of the C3 and C4 complexes could be competed with sequences upstream of DC 8, a gene that is coordinately expressed with DC 59 during embryo development. DNase I footprinting analysis revealed that nuclear extracts from embryos bound to four AT-rich sequences, and the protected motifs within fragment V were located in the highly homologous upstream regions of DC 59 and DC 8 genes.