The Vascular System of the Wheat Spikelet

1985 ◽  
Vol 12 (5) ◽  
pp. 487 ◽  
Author(s):  
T.P O'Brien ◽  
M.E Sammut ◽  
J.W Lee ◽  
M.G Smart
Keyword(s):  
Cross Section ◽  
Vascular Tissue ◽  
Vascular System ◽  
Histological Study ◽  
Cell Types ◽  
Dimensional Model ◽  
3 Dimensional ◽  
Attachment Region ◽  
Important Pathway ◽  
Different Cell Types

The attachment region of a mid-spike spikelet was sectioned serially. These sections were used to construct an accurate 3-dimensional model of the course of the vascular system that supplies the organs of the a and b florets, and the rachilla of the c and d florets. All organs are interconnected by vascular tissue, but certain parts of the system are phloem-only. In particular, the supply to the groove bundle of the pericarp, widely held to be the most important pathway to the grain, is made via an annulus of phloem to which lemma, palea and lodicules have phloem-only connections. The vascular system is sufficiently different from the pattern encountered in vegetative nodes to warrant treatment sui generis. The relationships between different cell types need greater histological study, especially in the complex composite bundles. This analysis shows that bundle shape in cross-section and the arrangement of xylem and phloem vary sharply over very short distances (100 ~ m ) .T he distribution of xylem and phloem transfer cells agrees with the proposal that significant solute relocation takes place in the regions where the vascular supplies to different organs meet. The area in the ovary neck that encompasses the fusion zone of the supplies to lemma, palea and pericarp emerges as a zone in need of detailed study, both in spikelet positions within a cultivar of known, but different, grain performance, and as a region to analyse for inter-cultivar comparisons.

Localization of Angiotensin II Type 1 receptor gene expression in rodent and human kidneys

2021 ◽  
Author(s):  
Julia Schrankl ◽  
Michaela Fuchs ◽  
Katharina Broeker ◽  
Christoph Daniel ◽  
Armin Kurtz ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Mesangial Cells ◽  
Vascular System ◽  
Receptor Gene ◽  
Cell Types ◽  
Receptor Expression ◽  
Ang Ii ◽  
Comprehensive Overview ◽  
Different Cell Types

The kidneys are an important target for angiotensin II (ANG II). In the adult kidneys the effects of ANG II are mediated mainly by ANG II type 1 (AT1) receptors. AT1 receptor expression has been reported for a variety of different cell types within the kidneys, suggesting a broad spectrum of actions for ANG II. Since there have been heterogeneous results in the literature regarding the intrarenal distribution of AT1 receptors, this study aimed to obtain a comprehensive overview about the localization of AT1 receptor expression in mouse, rat and human kidneys. Using the cell specific and high-resolution RNAscope technique, we performed colocalization studies with various cell markers to specifically discriminate between different segments of the tubular and vascular system. Overall we found a similar pattern of AT1 mRNA expression in mouse, rat and human kidneys. AT1 receptors were detected in mesangial cells and renin-producing cells. In addition, AT1 mRNA was found in interstitial cells of the cortex and outer medulla. In rodents, late afferent and early efferent arterioles expressed AT1 receptor mRNA, but larger vessels of the investigated species showed no AT1 expression. Tubular expression of AT1 mRNA was species-dependent with a strong expression in proximal tubules of mice while expression was undetectable in human tubular cells. These findings suggest that the (juxta)glomerular area and the tubulointerstitium are conserved expression sites for AT1 receptors across species and might present the main target sites for ANG II in adult human and rodent kidneys.

Tissue Interactions in Neural Crest Cell Development and Disease

Science ◽  
2013 ◽  
Vol 341 (6148) ◽  
pp. 860-863 ◽  
Author(s):  
Yoshiko Takahashi ◽  
Douglas Sipp ◽  
Hideki Enomoto
Keyword(s):  
Neural Crest ◽  
Vascular System ◽  
Neural Crest Cell ◽  
Hirschsprung Disease ◽  
Cell Types ◽  
Microbial Pathogens ◽  
Environmental Signals ◽  
Tissue Interactions ◽  
Migratory Cells ◽  
Different Cell Types

The neural crest is a transient population of migratory cells in the embryo that gives rise to a wide variety of different cell types, including those of the peripheral nervous system. Dysfunction of neural crest cells (NCCs) is associated with multiple diseases, such as neuroblastoma and Hirschsprung disease. Recent studies have identified NCC behaviors during their migration and differentiation, with implications for their contributions to development and disease. Here, we describe how interactions between cells of the neural crest and lineages such as the vascular system, as well as those involving environmental signals and microbial pathogens, are critically important in determining the roles played by these cells.

scholarly journals A RING Domain Gene Is Expressed in Different Cell Types of Leaf Trace, Stem, and Juvenile Bundles in the Stem Vascular System of Zinnia

2005 ◽  
Vol 138 (3) ◽  
pp. 1383-1395 ◽  
Author(s):  
Preeti Dahiya ◽  
Dimitra Milioni ◽  
Brian Wells ◽  
Nicola Stacey ◽  
Keith Roberts ◽  
...  
Keyword(s):  
Vascular System ◽  
Cell Types ◽  
Ring Domain ◽  
Leaf Trace ◽  
Different Cell Types

Genetic control of identity and growth in the early Arabidopsis embryo

2014 ◽  
Vol 42 (2) ◽  
pp. 346-351 ◽  
Author(s):  
Dolf Weijers
Keyword(s):  
Stem Cells ◽  
Plant Development ◽  
Vascular Tissue ◽  
Cell Types ◽  
Model System ◽  
Tissue Formation ◽  
Subsequent Growth ◽  
Future Challenges ◽  
Different Cell Types ◽  
Embryonic Root

Plants can grow complex and elaborate structures, in some species for thousands of years. Despite the diversity in form and shape, plants are built from a limited number of fundamental tissue types, and their arrangement is deeply conserved in the plant kingdom. A key question in biology is how these fundamental tissues, i.e. epidermal, ground and vascular tissue, are specified and organized in time and space. In the present paper, I discuss the use of the early Arabidopsis embryo as a model system to dissect the control of tissue formation and patterning, as well as the specification of the stem cells that sustain post-embryonic growth. I present recent insights into the molecules and mechanisms that control both the specification and the subsequent growth of the different cell types within the embryonic root. Finally, I discuss major unanswered questions and future challenges in using the embryo as a model to decipher the regulatory logic of plant development.

scholarly journals Specific and dynamic lignification at the cell-type level controls plant physiology and adaptability

2021 ◽  
Author(s):  
Delphine Ménard ◽  
Leonard Blaschek ◽  
Konstantin Kriechbaum ◽  
Cheng Choo Lee ◽  
Chuantao Zhu ◽  
...  
Keyword(s):  
Hydraulic Properties ◽  
Vascular Tissue ◽  
Biological Significance ◽  
Cell Types ◽  
Environmental Constraints ◽  
Cell Type ◽  
Pluripotent Cell ◽  
Whole Plants ◽  
Different Cell Types ◽  
Conduction Properties

Lignins, abundant phenolic cell wall polymers that accumulate in vascular tissue, were essential for plant terrestrialization as they enable sap conduction and mechanical support. Although lignification is currently understood as a random process, different cell types accumulate lignins with different compositions. The biological significance of these cellular differences is however still unknown. We performed single cell analyses to decipher the specific roles of different lignins and their residues on sap conduction and mechanical strengthening in plant xylem, using inducible pluripotent cell cultures and genetically modified whole plants. We show that specific lignins dynamically accumulate in each cell type and their morphotypes using distinct genetic programs, and that different lignin residues have non-redundant roles on plant biomechanical and hydraulic properties. Lignin is therefore a dynamic polymer changing composition to tailor the load bearing and sap conduction properties of each cells, in order for plants to adapt to developmental and environmental constraints.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Correlative transmission and high-resolution scanning electron microscopic studies on pituitary cells

1990 ◽  
Vol 48 (3) ◽  
pp. 20-21
Author(s):  
S. Tai
Keyword(s):  
Cell Types ◽  
Depth Of Field ◽  
Secretory Cells ◽  
Specific Cell ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
3 Dimensional ◽  
Microscopic Studies ◽  
Structure And Activity ◽  
Intracellular Structure

Extensive cytological and histological research, correlated with physiological experimental analysis, have been done on the anterior pituitaries of many different vertebrates which have provided the knowledge to create the concept that specific cell types synthesize, store and release their specific hormones. These hormones are stored in or associated with granules. Nevertheless, there are still many doubts - that need further studies, specially on the ultrastructure and physiology of these endocrine cells during the process of synthesis, transport and secretion, whereas some new methods may provide the information about the intracellular structure and activity in detail.In the present work, ultrastructural study of the hormone-secretory cells of chicken pituitaries have been done by using TEM as well as HR-SEM, to correlate the informations obtained from 2-dimensional TEM micrography with the 3-dimensional SEM topographic images, which have a continous surface with larger depth of field that - offers the adventage to interpretate some intracellular structures which were not possible to see using TEM.

Processing and Characterization of Recombinant von Willebrand Factor Expressed in Different Cell Types Using a Vaccinia Virus Vector

1992 ◽  
Vol 67 (01) ◽  
pp. 154-160 ◽  
Author(s):  
P Meulien ◽  
M Nishino ◽  
C Mazurier ◽  
K Dott ◽  
G Piétu ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Von Willebrand Factor ◽  
Human Fibroblasts ◽  
Active Form ◽  
Cell Types ◽  
Biologically Active ◽  
L Cells ◽  
Von Willebrand ◽  
Different Cell Types ◽  
Willebrand Factor

SummaryThe cloning of the cDNA encoding von Willebrand factor (vWF) has revealed that it is synthesized as a large precursor (pre-pro-vWF) molecule and it is now clear that the prosequence or vWAgll is responsible for the intracellular multimerization of vWF. We have cloned the complete vWF cDNA and expressed it using a recombinant vaccinia virus as vector. We have characterized the structure and function of the recombinant vWF (rvWF) secreted from five different cell types: baby hamster kidney (BHK), Chinese hamster ovary (CHO), human fibroblasts (143B), mouse fibroblasts (L) and primary embryonic chicken cells. Forty-eight hours after infection, the quantity of vWF antigen found in the cell supernatant varied from 3 to 12 U/dl depending on the cell type. By SDS-agarose gel electrophoresis, the percentage of high molecular weight forms of vWF varied from 39 to 49% relative to normal plasma for BHK, CHO, 143B and chicken cells but was less than 10% for L cells. In all cell types, the two anodic subbands of each multimer were missing. The two cathodic subbands were easily detected only in BHK and L cells. By SDS-PAGE of reduced samples, pro-vWF was present in similar quantity to the fully processed vWF subunit in L cells, present in moderate amounts in BHK and CHO and in very low amounts in 143B and chicken cells. rvWF from all cells bound to collagen and to platelets in the presence of ristocetin, the latter showing a high correlation between binding efficiency and degree of multimerization. rvWF from all cells was also shown to bind to purified FVIII and in this case binding appeared to be independent of the degree of multimerization. We conclude that whereas vWF is naturally synthesized only by endothelial cells and megakaryocytes, it can be expressed in a biologically active form from various other cell types.

Role of Transcriptional Read-Through in PRE Activity in Drosophila melanogaster

Acta Naturae ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 79-86 ◽  
Author(s):  
P. V. Elizar’ev ◽  
D. V. Lomaev ◽  
D. A. Chetverina ◽  
P. G. Georgiev ◽  
M. M. Erokhin
Keyword(s):  
Dna Sequences ◽  
Cell Types ◽  
Transcription Terminator ◽  
Response Elements ◽  
Polycomb Response Elements ◽  
The Individual ◽  
Multicellular Organisms ◽  
Different Cell Types ◽  
Main Factor

Maintenance of the individual patterns of gene expression in different cell types is required for the differentiation and development of multicellular organisms. Expression of many genes is controlled by Polycomb (PcG) and Trithorax (TrxG) group proteins that act through association with chromatin. PcG/TrxG are assembled on the DNA sequences termed PREs (Polycomb Response Elements), the activity of which can be modulated and switched from repression to activation. In this study, we analyzed the influence of transcriptional read-through on PRE activity switch mediated by the yeast activator GAL4. We show that a transcription terminator inserted between the promoter and PRE doesnt prevent switching of PRE activity from repression to activation. We demonstrate that, independently of PRE orientation, high levels of transcription fail to dislodge PcG/TrxG proteins from PRE in the absence of a terminator. Thus, transcription is not the main factor required for PRE activity switch.

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