Floral histogenesis in the Monocotyledons. IV. The Liliaceae

1960 ◽  
Vol 8 (3) ◽  
pp. 213 ◽  
Author(s):  
C Barnard
Keyword(s):  
Early Ontogeny ◽  
Periclinal Division ◽  
Flower Primordia ◽  
Independent Origin ◽  
Tunica Layer ◽  
Floral Histogenesis ◽  
In Cells

An account is presented of floral histogenesis in Bulbine bulbosa R.Br. and Stypandra glauca R.Br. The apex of the floral axis in both species has a two-layered tunica, and bracts arise through the periclinal division of cells of the inner layer of the tunica (hypodermis). In Bulbine, axillary flower primordia are initiated in the periclinal division of subhypodermal cells; in Stypandra the flower primordia are terminal and arise directly from the apices of branches of the inflorescence. In both species the perianth'members originate, in the same manner as the bracts, through periclinal divisions in cells of the hypodermis. Periclinal divisions may occur in the cells of the outer tunica layer (dermatogen) after the prinlordia are well formed. Divisions in subhypodermal cells in the area of perianth initiation are associated with the formation of a provascular strand and it is doubtful if such divisions contribute anything to the tissue of the perianth primordium itself. The stamens are initiated in the periclinal division of both hypodermal and subhypodermal cells. In Bulbine the carpels develop through periclinal divisions in the hypodermis and dermatogen. The placentas appear to arise through divisions in subhypodermal cells as structures adnate to the carpels. In Stypandra the carpels arise in a quite different manner through the periclinal division of subhypodermal cells. The margins of the carpels develop as the placentas and there is no suggestion in the early ontogeny of the gynaecium that the placentas have an independent origin.

Floral histogenesis in the Monocotyledons. II. The Cyperaceae

1957 ◽  
Vol 5 (2) ◽  
pp. 115 ◽  
Author(s):  
C Barnard
Keyword(s):  
General Pattern ◽  
Periclinal Division ◽  
Flower Primordia ◽  
Stamen Primordia ◽  
Scirpus Validus ◽  
Floral Bracts ◽  
Floral Histogenesis ◽  
In Cells

An account is presented of floral histogenesis in Scirpus validus Vahl, Cyperus eragrostis Lam., and Carex appressa R. Br. The cells of the apex of the spikelet in the three species are arranged in a two-layered tunica over a central corpus. Histogenetically the outer and inner tunica layers behave differently and are termed dermatogen and hypodermis respectively. The same three tissue zones are recognized in the flower primordia. Periclinal division of dermatogen and hypodermal cells gives rise to (i) the glumes or floral bracts and carpels in all species, (ii) the perianth members in Scirpus, and (iii) the perigynium in Carex. These are all classified as foliar organs. Periclinal divisions in cells of the outer corpus layers, and inclined and periclinal divisions in the hypodermis, characterize the formation of flower and stamen primordia. Periclinal division of dermatogen cells never occurs. These organs are regarded as cauline. The ovule develops directly from the growing point of the flower primordium and its integuments arise in the foliar fashion. The general pattern of histogenesis is compared with that in the Gramineae. Variations within this pattern and the interpretation of the floral structures are discussed.

Floral histogenesis in the monocotyledons. I. The Gramineae

1957 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
C Barnard
Keyword(s):  
Periclinal Division ◽  
The Other ◽  
Flower Primordia ◽  
Stamen Primordia ◽  
Other Hand ◽  
Previous Communication ◽  
Representative Species ◽  
Constant Feature ◽  
Floral Histogenesis

The pattern of floral histogenesis in a representative species from each of six tribes of the Gramineae is shown to be similar to that described in a previous communication for Triticum. Periclinal division of sub-hypodermal cells characterizes the origin of spikelet, flower, and stamen primordia. Periclinal divisions also occur in hypodermal cells during flower and stamen formation; and such divisions are more frequent at stamen initiation than at the initiation of flower primordia. Periclinal division of dermatogen cells never occurs during the formation of these organs, but is, on the other hand, a constant feature in the formation of glumes, lemma, palea, lodicules, and carpel. The hypodermis always contributes to the tissues of the glume and lemma primordia; it less frequently contributes to the tissues of the lodicule and palea, and only occasionally to that of the carpel. The morphology of the gramineous flower is discussed on the basis of floral histogenesis and the pattern of prorascular tissues in the gynaeceum. The literature dealing with floral histogenesis and the pattern of prorascular tissues in the gynaeceum.

Floral histogenesis in the monocotyledons. III. The Juncaceae

1958 ◽  
Vol 6 (4) ◽  
pp. 285 ◽  
Author(s):  
C Barnard
Keyword(s):  
Cell Division ◽  
The Other ◽  
Flower Primordia ◽  
Other Hand ◽  
Tunica Layer ◽  
Morphological Nature ◽  
Floral Histogenesis

An account is presented of floral histogenesis in Luzula campestris (L.) DC., Juncus articulatus L., and Juncus vaginatus R. Br. The pattern of floral histogenesis in these species is similar to that in species of the Gramineae and Cyperaceae. Bracts, bracteoles, perianth members, and carpellary tissue arise by divisions of cells of the tunica. Periclinal divisions in the outer tunica layer (dermatogen) always occur in the initiation of these "foliar" type organs. The primordia of inflorescence branches, flower primordia, and stamens, on the other hand, arise as a result of cell division in the outer layers of the corpus and the inner layer of the tunica. Periclinal divisions in the dermatogen are not involved in the differentiation of these "cauline" type structures. The morphological nature of the placentas in Juncus is discussed; they appear to arise independently of the carpellary tissue and after the manner of "cauline" structures. The ovules in both Luzula and Juncus arise in similar fashion.

Histogenesis of the inflorescence and flower of Triticum aestivum L.

1955 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
C Barnard
Keyword(s):  
Triticum Aestivum ◽  
Outer Layer ◽  
Apical Meristem ◽  
Floral Morphology ◽  
Triticum Aestivum L ◽  
Leaf Primordia ◽  
Periclinal Division ◽  
Flower Primordia ◽  
Foliage Leaf ◽  
Vegetative Buds

In Triticum the apical meristem of the spike and spikelets is similar to that of the vegetative axis: a two-layered tunica encloses a central corpus. Leaf primordia arise by the periclinal division of cells of the tunica, the corpus contributing nothing to their development. Spikelet primordia are initiated in periclinal divisions of cells of the outer layer of the corpus (sub-hypodermis). Their mode of origin is comparable with that of vegetative buds. The glumes and lemmas arise in the same manner as the foliage leaf; the flower primordia by divisions in the sub-hypodermis like the spikelets. The early histogenesis of the palea, lodicules, and carpel is also essentially the same as that of the foliage leaf, whilst the stamens arise as cauline structures like the spikelets and flower primordia. The ovule is derived directly from the apex of the flower primordium and the integuments originate in the manner of foliar structures. The significance of these observations in the interpretation of the floral morphology of Triticum is discussed.

Initiation of floral organs in Nicotiana tabacum

1973 ◽  
Vol 51 (9) ◽  
pp. 1611-1617 ◽  
Author(s):  
G. S. Hicks
Keyword(s):  
Nicotiana Tabacum ◽  
Periclinal Division ◽  
Floral Organs ◽  
Floral Buds ◽  
Tunica Layer ◽  
Routine Procedures

Floral buds of Nicotiana tabacum were fixed, sectioned, and stained by routine procedures, then analyzed microscopically. Initiation and emergence of all four classes of floral organs involved periclinal division in the second tunica layer (T2) and division of corpus cells. The extent of periclinal T2 divisions was different in different organs. Plasmolysis of tunica and corpus cells was observed at organ sites. The results generally parallel those of other studies.

Cytoplasmic Tubules in Cells Infected with Laryngotracheitis Virus

1969 ◽  
Vol 27 ◽  
pp. 376-377
Author(s):  
A. M. Watrach
Keyword(s):  
Tissue Culture ◽  
Small Proportion ◽  
Chicken Embryo ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Morphologic Characteristics ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus ◽  
In Cells

During a study of the development of infectious laryngotracheitis (LT) virus in tissue culture cells, unusual tubular formations were found in the cytoplasm of a small proportion of the affected cells. It is the purpose of this report to describe the morphologic characteristics of the tubules and to discuss their possible association with the development of virus.The source and maintenance of the strain of LT virus have been described. Prior to this study, the virus was passed several times in chicken embryo kidney (CEK) tissue culture cells.

Effect of Some Metabolic Inhibitors on Vinblastine-Induced Ribosomal-Granular Material Complexes

1971 ◽  
Vol 29 ◽  
pp. 548-549
Author(s):  
Awtar Krishan ◽  
Dora Hsu
Keyword(s):  
Granular Material ◽  
Rna Synthesis ◽  
Culture Medium ◽  
Actinomycin D ◽  
Metabolic Inhibitors ◽  
Protein And Rna Synthesis ◽  
Apparent Reduction ◽  
Plant Alkaloids ◽  
In Cells

Cells exposed to antitumor plant alkaloids, vinblastine and vincristine sulfate have large proteinacious crystals and complexes of ribosomes, helical polyribosomes and electron-dense granular material (ribosomal complexes) in their cytoplasm, Binding of H3-colchicine by the in vivo crystals shows that they contain microtubular proteins. Association of ribosomal complexes with the crystals suggests that these structures may be interrelated.In the present study cultured human leukemic lymphoblasts (CCRF-CEM), were incubated with protein and RNA-synthesis inhibitors, p. fluorophenylalanine, puromycin, cycloheximide or actinomycin-D before the addition of crystal-inducing doses of vinblastine to the culture medium. None of these compounds could completely prevent the formation of the ribosomal complexes or the crystals. However, in cells pre-incubated with puromycin, cycloheximide, or actinomycin-D, a reduction in the number and size of the ribosomal complexes was seen. Large helical polyribosomes were absent in the ribosomal complexes of cells treated with puromycin, while in cells exposed to cycloheximide, there was an apparent reduction in the number of ribosomes associated with the ribosomal complexes (Fig. 2).

Detection of Nucleic Acids in Cells or Tissue Sections Using In situ Polymerase Chain Reaction (PCR)

1996 ◽  
Vol 54 ◽  
pp. 16-17
Author(s):  
J. R. Hully ◽  
K. R. Luehrsen ◽  
K. Aoyagi ◽  
C. Shoemaker ◽  
R. Abramson
Keyword(s):  
Nucleic Acids ◽  
Viral Infections ◽  
Anatomical Location ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Cellular Source ◽  
Gene Transcripts ◽  
Initial Description ◽  
In Cells

The development of PCR technology has greatly accelerated medical research at the genetic and molecular levels. Until recently, the inherent sensitivity of this technique has been limited to isolated preparations of nucleic acids which lack or at best have limited morphological information. With the obvious exception of cell lines, traditional PCR or reverse transcription-PCR (RT-PCR) cannot identify the cellular source of the amplified product. In contrast, in situ hybridization (ISH) by definition, defines the anatomical location of a gene and/or it’s product. However, this technique lacks the sensitivity of PCR and cannot routinely detect less than 10 to 20 copies per cell. Consequently, the localization of rare transcripts, latent viral infections, foreign or altered genes cannot be identified by this technique. In situ PCR or in situ RT-PCR is a combination of the two techniques, exploiting the sensitivity of PCR and the anatomical definition provided by ISH. Since it’s initial description considerable advances have been made in the application of in situ PCR, improvements in protocols, and the development of hardware dedicated to in situ PCR using conventional microscope slides. Our understanding of the importance of viral latency or viral burden in regards to HIV, HPV, and KSHV infections has benefited from this technique, enabling detection of single viral copies in cells or tissue otherwise thought to be normal. Clearly, this technique will be useful tool in pathobiology especially carcinogenesis, gene therapy and manipulations, the study of rare gene transcripts, and forensics.

Absence of temporal ordering of apoptotic features in heat-shock treated leukemia and lymphoma cell lines

1996 ◽  
Vol 54 ◽  
pp. 758-759
Author(s):  
D. W. Fairbain ◽  
M.D. Standing ◽  
K.L. O'Neill
Keyword(s):  
Heat Shock ◽  
Cell Lines ◽  
Chromatin Condensation ◽  
Membrane Integrity ◽  
Resistant Cell ◽  
Membrane Blebbing ◽  
Late Loss ◽  
Induced Apoptosis ◽  
Dying Cells ◽  
In Cells

Apoptosis is a genetically defined response to physiological stimuli that results in cellular suicide. Features common to apoptotic cells include chromatin condensation, oligonucleosomal DNA fragmentation, membrane blebbing, nuclear destruction, and late loss of ability to exclude vital dyes. These characteristics contrast markedly from pathological necrosis, in which membrane integrity loss is demonstrated early, and other features of apoptosis, which allow a non-inflammatory removal of dead and dying cells, are absent. Using heat shock-induced apoptosis as a model for examining stress response in cells, we undertook to categorize a variety of human leukemias and lymphomas with regard to their response to heat shock. We were also interested in determining whether a common temporal order was followed in cells dying by apoptosis. In addition, based on our previous results, we investigated whether increasing heat load resulted in increased apoptosis, with particular interest in relatively resistant cell lines, or whether the mode of death changed from apoptosis to necrosis.

Umatilla Virus Association with Fibrils and Tubules in Cultured Cells

1980 ◽  
Vol 38 ◽  
pp. 476-477
Author(s):  
Neil M. Foster ◽  
Ruth D. Breckon
Keyword(s):  
Bluetongue Virus ◽  
Linear Array ◽  
Cultured Cells ◽  
Intimate Association ◽  
Infected Cells ◽  
Dark Staining ◽  
In Cells

Macrotubules have been described1 in cells infected with Umatilla virus (UMAV), an orbivirus for which bluetongue virus (BTV) is the protype. Macrotubules, often in linear array, were observed in the cytoplasm and in intimate association with viroplasms of infected cells. Macrotubules had outside and inside diameters of 20 and 15 nm and many had dark-staining centers with diameters similar to the interiors of the tubules. UMAV was 60 nm and the RNA core was 30 nm in diameter. This report describes the association of UMAV with macrotubules and two types of microtubules.

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