scholarly journals Anatomical observations on the influence of morphactin on wood formation of Carpinus betulus L. and Syringa vulgaris L. shoots

2013 ◽  
Vol 33 (1) ◽  
pp. 103-107 ◽  
Author(s):  
M. Smoliński ◽  
M. Saniewski ◽  
J. Pieniążek ◽  
J. E. Phelps ◽  
E. A. McGinnes, Jr.
Keyword(s):  
Cell Polarity ◽  
Cellular Differentiation ◽  
Auxin Transport ◽  
Transverse Section ◽  
Longitudinal Axis ◽  
Cell Types ◽  
Wood Formation ◽  
Carpinus Betulus ◽  
Basipetal Auxin Transport

The effect of morphactin IT 3456 on wood differentiation in <em>Carptinus betulus</em> and <em>Syringa vulgaris</em> was studied. In both species morphactin strongly stimulated production of wood but xylary differentiation was abnormal. Cellular differentiation was altered in that vessels were considerably smaller on transverse section and shorter than normal. Fibers and tracheids were also much ,shorter. It appeared that all cell types were disorientated from their longitudinal axis. It is probable that the effect of morphactin is caused by an inhibition of basipetal auxin transport and by the disturbance of general cell polarity during cambial divisions.

The Developmental Capacity of Nuclei taken from Intestinal Epithelium Cells of Feeding Tadpoles

Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 622-640 ◽  
Author(s):  
J. B. Gurdon
Keyword(s):  
Genetic Information ◽  
Cellular Differentiation ◽  
Cell Types ◽  
Nuclear Transplantation ◽  
Differentiated Cells ◽  
Developmental Capacity ◽  
Nuclear Changes ◽  
Different Cell Types ◽  
Epithelium Cells ◽  
Saline Medium

An important problem in embryology is whether the differentiation of cells depends upon a stable restriction of the genetic information contained in their nuclei. The technique of nuclear transplantation has shown to what extent the nuclei of differentiating cells can promote the formation of different cell types (e.g. King & Briggs, 1956; Gurdon, 1960c). Yet no experiments have so far been published on the transplantation of nuclei from fully differentiated normal cells. This is partly because it is difficult to obtain meaningful results from such experiments. The small amount of cytoplasm in differentiated cells renders their nuclei susceptible to damage through exposure to the saline medium, and this makes it difficult to assess the significance of the abnormalities resulting from their transplantation. It is, however, very desirable to know the developmental capacity of such nuclei, since any nuclear changes which are necessarily involved in cellular differentiation must have already taken place in cells of this kind.

Cell polarity and tissue patterning in plants

Development ◽  
1991 ◽  
Vol 113 (Supplement_1) ◽  
pp. 83-93 ◽  
Author(s):  
Tsvi Sachs
Keyword(s):  
Cell Polarity ◽  
Cell Shape ◽  
Auxin Transport ◽  
Developmental Stages ◽  
Important Determinant ◽  
Genetic System ◽  
Cell Patterning ◽  
Cell Polarization ◽  
Sources And Sinks ◽  
Tissue Patterning

Cell polarization is the specialization of developmental events along one orientation or one direction. Such polarization must be an early, essential stage of tissue patterning. The specification of orientation could not occur only at the level of the genetic system and it must express a coordination of events in many cells. There is a positive feedback relation between cell polarization and the transport of the known hormone auxin: polarity determines oriented auxin transport while transport itself induces both new and continued polarization. Since cell polarization increases gradually, this feedback leads to the canalization of transport – and of the associated cell differentiation – along defined strands of specialized cells. Recent work has shown that the same canalized flow can also be an important determinant of cell shape. In primordial, embryonic regions cell growth is oriented along the flow of auxin from the shoot towards the root. In later developmental stages the cells respond to the same flow by growing in girth, presumably adjusting the capacity of the tissues to the flow of signals. Finally, disrupted flow near wounds results in the development of relatively unorganized callus. Continued callus development appears to require the participation of the cells, as sources and sinks of auxin and other signals. The overall picture to emerge suggests that cell patterning can result from competition between cells acting as preferred channels, sources and sinks for developmental signals.

Role of basipetal auxin transport and lateral auxin movement in rooting and growth of etiolated lupin hypocotyls

2004 ◽  
Vol 121 (2) ◽  
pp. 294-304 ◽  
Author(s):  
Juana Ines Lopez Nicolas ◽  
Manuel Acosta ◽  
Jose Sanchez-Bravo
Keyword(s):  
Auxin Transport ◽  
Basipetal Auxin Transport

scholarly journals Ion Channels and Early Development of Neural Cells

1998 ◽  
Vol 78 (2) ◽  
pp. 307-337 ◽  
Author(s):  
KUNITARO TAKAHASHI ◽  
YASUSHI OKAMURA
Keyword(s):  
Ion Channels ◽  
Early Development ◽  
Cellular Differentiation ◽  
Neural Induction ◽  
Cell Types ◽  
Simple System ◽  
Optical Methods ◽  
Transcriptional Level ◽  
Neural Cells ◽  
Embryonic Cells

Takahashi, Kunitaro, and Yasushi Okamura. Ion Channels and Early Development of Neural Cells. Physiol. Rev. 78: 307–337, 1998. — In this review, we underscore the merits of using voltage-dependent ion channels as markers for neuronal differentiation from the early stages of uncommitted embryonic blastomeres. Furthermore, a fairly large part of the review is devoted to the descriptions of the establishment of a simple model system for neural induction derived from the cleavage-arrested eight-cell ascidian embryo by pairing a single ectodermal with a single vegetal blastomere as a competent and an inducer cell, respectively. The descriptions are focused particularly on the early developmental processes of various ion channels in neuronal and other excitable membranes observed in this extraordinarily simple system, and we compare these results with those in other significant and definable systems for neural differentiation. It is stressed that this simple system, for which most of the electronic and optical methods and various injection experiments are applicable, may be useful for future molecular physiological studies on the intracellular process of differentiation of the early embryonic cells. We have also highlighted the importance of suppressive mechanisms for cellular differentiation from the experimental results, such as epidermal commitment of the cleavage-arrested one-cell Halocynthia embryos or suppression of epidermal-specific transcription of inward rectifier channels by neural induction signals. It was suggested that reciprocal suppressive mechanisms at the transcriptional level may be one of the key processes for cellular differentiation, by which exclusivity of cell types is maintained.

ROLES OF AUXIN AND GIBBERELLIN IN GRAVITY-INDUCED TENSION WOOD FORMATION IN AESCULUS TURBINATA SEEDLINGS

IAWA Journal ◽  
2004 ◽  
Vol 25 (3) ◽  
pp. 337-347 ◽  
Author(s):  
Sheng Du ◽  
Hiroki Uno ◽  
Fukuju Yamamoto
Keyword(s):  
Tension Wood ◽  
Auxin Transport ◽  
Histological Analysis ◽  
Synergistic Effects ◽  
Wood Formation ◽  
Wood Fibers ◽  
Lower Side ◽  
Inhibitory Effects ◽  
Auxin Action ◽  
Ga Biosynthesis

The lowest nodes of 6-week-old Aesculus turbinata seedlings were treated with uniconazole-P, an inhibitor of gibberellin (GA) biosynthesis, or a mixture of uniconazole-P and GA3 in acetone solution. To the seedling stems, an inhibitor of auxin transport (NPA) or inhibitors of auxin action (raphanusanin or MBOA) were applied in lanolin paste. The seedlings were tilted at a 45° angle and kept for 10 weeks before histological analysis. Decreases in both normal and tension wood formation followed the application of uniconazole-P. The application of GA3 together with uniconazole-P partially negated the effect of uniconazole-P alone. The application of NPA inhibited tension wood formation at, above, and below the lanolin-treated portions. The treatment of raphanusanin or MBOA also resulted in decreases in tension wood formation at the treated portions. The inhibitory effects of these chemicals applied on the upper side of tilted stems or around the entire stem were greater than on the lower side. The application of uniconazole-P in combination with raphanusanin, MBOA or NPA showed synergistic effects on the inhibition of tension wood formation. The results suggest that both auxin and GA regulate the quantitative production of tension wood fibers and are essential to tension wood formation.

scholarly journals Mechanism of Eccentric Cardiomyocyte Hypertrophy Secondary to Severe Mitral Regurgitation

Circulation ◽  
2020 ◽  
Vol 141 (22) ◽  
pp. 1787-1799
Author(s):  
Shujuan Li ◽  
Ngoc Uyen Nhi Nguyen ◽  
Feng Xiao ◽  
Ivan Menendez-Montes ◽  
Yuji Nakada ◽  
...  
Keyword(s):  
Heart Disease ◽  
Mitral Regurgitation ◽  
Cell Polarity ◽  
Myocardial Dysfunction ◽  
Systolic Dysfunction ◽  
Mammalian Target Of Rapamycin ◽  
Longitudinal Axis ◽  
Cardiomyocyte Hypertrophy ◽  
Valve Repair ◽  
Lv Dysfunction

Background: Primary valvular heart disease is a prevalent cause of morbidity and mortality in both industrialized and developing countries. Although the primary consequence of valvular heart disease is myocardial dysfunction, treatment of valvular heart diseases centers around valve repair or replacement rather than prevention or reversal of myocardial dysfunction. This is particularly evident in primary mitral regurgitation (MR), which invariably results in eccentric hypertrophy and left ventricular (LV) failure in the absence of timely valve repair or replacement. The mechanism of LV dysfunction in primary severe MR is entirely unknown. Methods: Here, we developed the first mouse model of severe MR. Valvular damage was achieved by severing the mitral valve leaflets and chords with iridectomy scissors, and MR was confirmed by echocardiography. Serial echocardiography was performed to follow up LV morphology and systolic function. Analysis of cardiac tissues was subsequently performed to evaluate valve deformation, cardiomyocyte morphology, LV fibrosis, and cell death. Finally, dysregulated pathways were assessed by RNA-sequencing analysis and immunofluorescence. Results: In the ensuing 15 weeks after the induction of MR, gradual LV dilatation and dysfunction occurred, resulting in severe systolic dysfunction. Further analysis revealed that severe MR resulted in a marked increase in cardiac mass and increased cardiomyocyte length but not width, with electron microscopic evidence of sarcomere disarray and the development of sarcomere disruption. From a mechanistic standpoint, severe MR resulted in activation of multiple components of both the mammalian target of rapamycin and calcineurin pathways. Inhibition of mammalian target of rapamycin signaling preserved sarcomeric structure and prevented LV remodeling and systolic dysfunction. Immunohistochemical analysis uncovered a differential pattern of expression of the cell polarity regulator Crb2 (crumbs homolog 2) along the longitudinal axis of cardiomyocytes and close to the intercalated disks in the MR hearts. Electron microscopy images demonstrated a significant increase in polysome localization in close proximity to the intercalated disks and some areas along the longitudinal axis in the MR hearts. Conclusions: These results indicate that LV dysfunction in response to severe MR is a form of maladaptive eccentric cardiomyocyte hypertrophy and outline the link between cell polarity regulation and spatial localization protein synthesis as a pathway for directional cardiomyocyte growth.

scholarly journals The Emerging Role of Galectins and O-GlcNAc Homeostasis in Processes of Cellular Differentiation

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1792 ◽  
Author(s):  
Rada Tazhitdinova ◽  
Alexander V. Timoshenko
Keyword(s):  
Cancer Biology ◽  
Cellular Differentiation ◽  
Current Knowledge ◽  
Expression Profiles ◽  
Cell Types ◽  
Innovative Strategies ◽  
Protein Levels ◽  
Differentiated Cells ◽  
Independent Functions

Galectins are a family of soluble β-galactoside-binding proteins with diverse glycan-dependent and glycan-independent functions outside and inside the cell. Human cells express twelve out of sixteen recognized mammalian galectin genes and their expression profiles are very different between cell types and tissues. In this review, we summarize the current knowledge on the changes in the expression of individual galectins at mRNA and protein levels in different types of differentiating cells and the effects of recombinant galectins on cellular differentiation. A new model of galectin regulation is proposed considering the change in O-GlcNAc homeostasis between progenitor/stem cells and mature differentiated cells. The recognition of galectins as regulatory factors controlling cell differentiation and self-renewal is essential for developmental and cancer biology to develop innovative strategies for prevention and targeted treatment of proliferative diseases, tissue regeneration, and stem-cell therapy.

scholarly journals Drosophila aPKC regulates cell polarity and cell proliferation in neuroblasts and epithelia

2003 ◽  
Vol 163 (5) ◽  
pp. 1089-1098 ◽  
Author(s):  
Melissa M. Rolls ◽  
Roger Albertson ◽  
Hsin-Pei Shih ◽  
Cheng-Yu Lee ◽  
Chris Q. Doe
Keyword(s):  
Cell Proliferation ◽  
Cell Polarity ◽  
Cell Types ◽  
Proper Function ◽  
Larval Stages ◽  
Kinase C ◽  
Discs Large ◽  
Lethal Giant Larvae ◽  
Cell Diversity ◽  
Apical Localization

Cell polarity is essential for generating cell diversity and for the proper function of most differentiated cell types. In many organisms, cell polarity is regulated by the atypical protein kinase C (aPKC), Bazooka (Baz/Par3), and Par6 proteins. Here, we show that Drosophila aPKC zygotic null mutants survive to mid-larval stages, where they exhibit defects in neuroblast and epithelial cell polarity. Mutant neuroblasts lack apical localization of Par6 and Lgl, and fail to exclude Miranda from the apical cortex; yet, they show normal apical crescents of Baz/Par3, Pins, Inscuteable, and Discs large and normal spindle orientation. Mutant imaginal disc epithelia have defects in apical/basal cell polarity and tissue morphology. In addition, we show that aPKC mutants show reduced cell proliferation in both neuroblasts and epithelia, the opposite of the lethal giant larvae (lgl) tumor suppressor phenotype, and that reduced aPKC levels strongly suppress most lgl cell polarity and overproliferation phenotypes.

scholarly journals N-glycan containing a core α1,3-fucose residue is required for basipetal auxin transport and gravitropic response in rice (Oryza sativa )

2016 ◽  
Vol 212 (1) ◽  
pp. 108-122 ◽  
Author(s):  
Rikno Harmoko ◽  
Jae Yong Yoo ◽  
Ki Seong Ko ◽  
Nirmal Kumar Ramasamy ◽  
Bo Young Hwang ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Auxin Transport ◽  
Gravitropic Response ◽  
Fucose Residue ◽  
Basipetal Auxin Transport
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