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71.
Callus was obtained from segments of immature inflorescence of Coix lacryma-jobi cultured on N6 medium containing 1–2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 3–5% sucrose. Plantlets were regenerated when embryogenic calluses were transferred onto MS medium with 0.5 mg/l kinetin and 0.01 mg/l naphthaleneacetic acid (NAA). Regenerated plants had the diploid chromosome number (2n=20). 相似文献
72.
Gideon W. Schaeffer F. T. Sharpe Jr. H. L. Carnahan C. W. Johnson 《Plant Cell, Tissue and Organ Culture》1986,6(2):149-157
Rice, Oryza sativa, plants regenerated from anther culture with and without in vitro selection pressure were evaluated for chalky seed. Progeny evaluated included 21 spontaneously doubled haploids selfed 4 times, progeny from plants regenerated from S-aminoethylcysteine resistant callus selfed 4 times and backcrosses of both types to the parental type. All lines with in vitro histories had higher seed chalkiness than the controls both in the intensity of chalkiness and in the number of seeds expressing the character. The full range of intensity and amount of chalkiness was expressed in the progeny. The average intensity of anther/tissue culture-derived progeny was 4–5, based on a scale of 1 (translucent) to 10 (fully opaque), and the average amount of chalkiness within plants sampled was 50–75 percent. The chalky characteristic is transmitted from parent to offspring into a range of identifiable F2 segregants.
Disclaimer statement Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the USDA, and does not imply its approval to the exclusion of other products that may also be suitable. 相似文献
73.
M. V. Gusev T. G. Korzhenevskaya L. V. Pyvovarova O. I. Baulina R. G. Butenko 《Planta》1986,167(1):1-8
Tobacco (Nicotiana tabacum L.) shoots associated with the nitrogen-fixing cyanobacterium Anabaena variabilis Kütz. (ATCC 29413) were regenerated in mixed cultures of tobacco callus and the cyanobacterium. The cyanobacteria were localized inside the tissues as well as on the surface of regenerated shoots, formed heterocysts, and were capable of acetylene reduction. 相似文献
74.
75.
Summary The caudal musculature of the free-swimming tadpole of the ascidian, B. schlosseri consists of cylindrical mononucleated cells connected in longitudinal rows flanking the axial notochord. During resorption of the larval tail, which is apparently induced by the contraction of the epidermis, muscle cells are dissociated and pushed into the body cavity where most of them are rapidly engulfed by phagocytes. In the initial stages of tail withdrawal muscle cells display surface alterations due to the disruption of intercellular junctions and disarrangement of myofibrils. Extensive degenerative changes, with shrinkage of mitochondria and disintegration of the contractile material are subsequently observed. Lysosomes and autophagic vacuoles are rarely seen and appear to play a secondary role in the degradation of the muscle cells, which occurs predominantly within the phagocytes. Myofilaments and myofibrils have never been observed within autophagic vacuoles. Clumps of muscle fragments and degenerated phagocytes undergo eventual dissolution in the blood lacunae, concomitantly with the differentiation of the young oozooid.This investigation was supported in part by a grant from the Muscular Dystrophy Associations of America and by CNR contract No. 7100396/04115542 from the Istituto di Biologia del Mare, Venice. We gratefully acknowledge the skillful assistance of Mr. G. Gallian, Mr. M. Fabbri and Mr. G. Tognon. We also thank the staff of the Stazione Idrobiologica at Chioggia for collecting the colonies. 相似文献
76.
Peter Böck 《Cell and tissue research》1970,105(3):389-404
Zusammenfassung Die Feinstruktur der chromaffinen paraganglionären Zellinseln im Endoneuralraum des Plexus suprarenalis wird beschrieben.Das paraganglionäre Gewebe liegt neben Kapillaren mit teilweise fenestrierten Endothelien und spärlich verstreuten Bindegewebszellen. Es wird von zwei Zellarten aufgebaut:Typ I-Zellen (chromaffine Zellen) mit großen, locker strukturierten Kernen enthalten im Zytoplasma elektronendichte Granula (1000–1600 Å Durchmesser) mit eng anliegender Membranbegrenzung und Vesikel von 2000–4000 Å Durchmesser, deren dichter Inhalt meist exzentrisch gelegen und durch einen weiten Spalt von der Membran getrennt ist. Weiters beobachtet man ausgedehnte Golgiregionen und in ihrer Nähe uncharakteristische (Entwicklungs-) Formen der beschriebenen Granula, Mitochondrien, Ergastoplasma und freie Ribosomen. Mikrotubuli und Plasmafilamente sind regelmäßig, multivesiculated bodies gelegentlich zu finden.Typ II-Zellen (Hüllzellen) bilden eine Basalmembran aus und umgeben die chromaffinen Zellen mit dünnen Fortsätzen. Die Zellorganellen sind in der Nähe des Kernes gelegen, die Fortsätze weisen eine dichte, z. T. geordnete, fibrilläre Strukturierung auf. An der Zelloberfläche beobachtet man regionäre Zytoplasmaverdichtungen. Die Hüllzellen enthalten keine Bläschen mit elektronendichtem Inhalt.Markfreie Nerven, in Schwannsche Zellen und Hüllzellen gelagert, ziehen an die Typ I-Zellen heran und bilden an deren Oberfläche synaptische Verbindungen aus. Dabei erscheinen die chromaffinen Zellen stets als postsynaptischer Teil der Formation.Die Typ I-Zellen werden als endokrin tätige Zellen aufgefaßt, die durch Abgabe von Katecholaminen hemmend auf die Impulstransmission wirken. Die Typ II-Zellen entsprechen den Schwannschen Zellen.
Fine structure of paraganglionic tissue in the suprarenal plexus of the guinea pig
Summary The fine structure of chromaffin paraganglionic tissue situated in the endoneural space of the plexus surparenalis is described.The paraganglionic tissue is found near capillaries with partially fenestrated endothelial cells and rarely scattered connective tissue cells. Two cell types are observed:Type I-cells (chromaffin cells) with great, fine structured nucleus show in their cytoplasm electron dense granules (1,000–1,600 Å in diameter) with clinching membranes and vesicles of 2,000 to 4,000 Å in diameter. In the latter the normally excentric situated dense core is separated from the membrane by a wide cleft. Further large Golgi areas and near them uncharacteristic (developing) kinds of the granules, as described above, mitochondria, ergastoplasm and ribosomes occur. Microtubules and filaments are regularely, multivesiculated bodies occasionally found.Type II-cells (surrounding cells) produce a basement membrane and envelope the chromaffin cells with fine processes. The cell organells are near the nucleus. The processes show a compact, partially fibrillar structure. On the cell surface condensations of the cytoplasm are observed in some regions. The surrounding cells do not contain vesicles with an electron dense core.Myelinated nerves, wrapped by Schwann cells and surrounding cells approach to type I-cells and build synaptic junctions to their surface. In such cases constantly the chromaffin cells are seen as the postsynaptic part of the formation.The type I-cells are thought to be of endocrine function, having an inhibitory effect on impulse transmission by secreting catecholamines. The type II-cells correspond to the cells of Schwann.相似文献
77.
Peter Böck 《Cell and tissue research》1970,110(2):243-257
Zusammenfassung Das Parenchym der peribronchialen Mikroparaganglien wird von zwei Zellarten aufgebaut: Chromaffine Zellen (Typ I-Zellen) und Hüllzellen (Typ II-Zellen).Die chromaffinen Zellen sind durch ihren reichen Gehalt an Vesikeln mit elektronendichtem Inhalt gekennzeichnet, deren Durchmesser 700–1300 Å beträgt. Markfreie Nerven ziehen an die Typ I-Zellen heran und bilden synaptische Kontakte aus. Die chromaffinen Zellen sind dabei der postsynaptische Teil der Verbindung. Die Hüllzellen entsprechen strukturell und funktionell den Schwannschen Zellen.Ein Mikroparaganglion wird von 10 bis 15 chromaffinen Zellen und deren Hüllzellen aufgebaut. Sie liegen dicht um fenestrierte Kapillaren, die von den Aa. bronchiales aus versorgt werden. Die Paraganglien sind von den Nervenzellen des peribronchialen Plexus durch dessen Perineurium getrennt. Selten findet man solitäre chromaffine Zellen innerhalb der Nervengeflechte. Es wird angenommen, daß die Paraganglien endokrine Funktionen erfüllen.
The fine structure of the guinea pig peribronchial micro-paraganglia
Summary The parenchyma of peribronchial microparaganglia consists of two different cell types: chromaffin cells (type I-cells) and surrounding cells (type II-cells).The chromaffin cells contain numerous vesicles with electron dense content, their diameter ranging from 700 to 1,300 Å. Unmyelinated nerves form synapses with type I-cells. The surrounding cells structurally and functionally correspond to Schwann cells.A micro-paraganglion consists of ten to fifteen chromaffin cells and their satellite cells. They are situated close to fenestrated capillaries, which are supplied from the Aa. bronchiales. A perineurial sheath separates the paraganglia from the nerve cells of the peribronchial plexus. Single chromaffin cells are found seldom within the nervous plexus.The paraganglia are thought to have an endocrine function.相似文献
78.
Philip S. Rudland Christine M. Hughes Sharon A. Ferns Michael J. Warburton 《In vitro cellular & developmental biology. Plant》1989,25(1):23-36
Summary Parenchymal organoidal structures that were obtained from collagenase digestion of reduction mammoplasty specimens of apparently
normal human breasts have been grown in short-term primary cultures, either on plastic or on floating gels of polymerized
rat-tail collagen. Three morphologically distinct major cell types are readily observed in both systems: cuboidal cells, which
occupy apical positions on collagen gels; larger, epithelioid, or basal cells on gels; and elongated cells which penetrate
into the gel. In addition, a fourth cell type, that of a large, flat cell, is observed less readily by phase contrast microscopy
on the surface of cultures grown on plastic. Immunofluorescent and immunocytochemical staining of cultures on plastic or histologic
sections of cultures on gels have been undertaken with antisera and other histochemical reagents that stain the different
parenchymal cell types in vivo. Thus antisera to epithelial membrane antigen(s), monoclonal antibodies (MABs) to the defatted
mammary milk fat globule membrane, peanut lectin, and keratin MAB LE61, which preferentially stain the epithelial cells of
ducts in vivo, also stain the cuboidal/apical cells in vitro. The large, flat cells are stained intensely by the first three
reagents but not by the last one. Antisera to collagen IV, laminin, fibronectin, actin, keratin MAB LP34, MABs to the common
acute lymphoblastic leukemia antigen, and MAB LICR-LON-23.10, which showed enhanced staining for the ductal myoepithelial
cells in vivo, also stain the epithelioid/elongated cells in vitro. However, the effect of the last four reagents is reduced
considerably in most elongated cells, and MAB LP34 stains the large, flat cells intensely. Heterogeneous cells of intermediate
morphologies and staining patterns between the cuboidal/flat cells and large epithelioid cells have also been identified.
The results suggest that the cuboidal cells and large, flat cells are related to mammary epithelial cells, whereas the large
epithelioid/elongated cells have some characteristics of myoepithelial cells, and that intermediate forms may exist in culture
between the two parenchymal cell types.
This work was supported in part by the Ludwig Institute for Cancer Research and the Cancer and Polio Research Fund. Dr. M.
J. Warburton is supported by the Cancer Research Campaign. 相似文献
79.
Heather J. Lawlor Jen A. McComb Michael A. Borowitzka 《Journal of applied phycology》1989,1(2):105-112
The effects of light quality and irradiance, and supply of organic carbon and vitamins on the growth of two forms of Ecklonia radiata in tissue culture were examined. A callus of unpigmented cells developed over the cut surface of newly excised explants of
stipe. This growth was best in the dark but stopped after 10 weeks. Pigmented, mainly filamentous clumps of cells developed
from explants after several weeks in culture. These required light for growth, with growth being enhanced by increasing photon
flux density up to 30 μmol photon m-2 s-1, with the active spectral component being red light (> 600 nm). The addition to the medium of a range of organic carbon sources
or vitamins did not stimulate growth of either culture type in the dark.
author for correspondence 相似文献
80.
Suman Singha Edwin C. Townsend Gene H. Oberly 《Plant Cell, Tissue and Organ Culture》1990,23(2):135-142
Shoot-tip cultures of Quince C (Cydonia oblonga Mill.) initiated on Murashige & Skoog (MS) medium containing 5 M BA and 0.6% Phytagar showed both shoot-tip necrosis and severe vitrification. Culturing explants on medium containing 1.2% Phytagar and Ca levels of 3 mM (MS medium), 18 mM and 30 mM showed a decrease in growth with increasing medium Ca levels, being especially severe at 30 mM. The Ca content of the explants increased linearly with increasing medium Ca. Culturing explants on medium containing 3 mM, 9 mM, and 18 mM Ca at 0.6, 0.9, and 1.2% agar resulted in reduction in growth, shoot-tip necrosis, and vitrification when either factor was increased. The reduction in shoot-tip necrosis could be accounted for primarily by an increase in medium Ca levels but may also be affected by a change in explant growth. Increasing Ca concentration in the medium resulted in a linear increase in explant K, Ca, Mg, and B levels and a decrease in Mn and Na. Although increasing medium Ca or agar levels reduced vitrification, it is unclear whether they were the direct cause of the reduction in vitrification or whether this response was an effect of the reduction in culture fresh weight.Approved by publication by the Director, West Virginia Agriculture anf Forestry Experimental Station as Scientific Article No. 2199 相似文献