Epidermis: Outer Cell Layer of the Plant

2010 ◽  
Author(s):  
Beverley J Glover
Keyword(s):  
Cell Layer ◽  
Outer Cell ◽  
Outer Cell Layer

Embryonic development of the heart

Development ◽  
1969 ◽  
Vol 22 (3) ◽  
pp. 333-348
Author(s):  
Francis J. Manasek
Keyword(s):  
Cell Layer ◽  
Embryonic Heart ◽  
Outer Cell ◽  
Chick Embryos ◽  
Myocardial Wall ◽  
Undifferentiated Cells ◽  
Epicardial Layer ◽  
Outer Cell Layer ◽  
Heart Wall

The mature heart may be thought of as consisting of three layers, endocardium, myocardium, and an outer investing tissue called the epicardium. During early formation of the tubular heart of chick embryos, at about the 8-somite stage, two tissue layers become clearly discernible with the light microscope: the endocardium and the developing myocardial wall. The outer epicardial layer does not appear until later in development. It is generally accepted that embryonic heart wall or ‘epimyocardium’ is composed of muscle and undifferentiated cells. As its name implies, the epimyocardium is thought to give rise to myocardium and epicardium. Kurkiewicz (1909) suggested that the epicardium was not an epimyocardial derivative but rather is formed from cells originating in the sinus venosus region, which migrate over the surface of the heart. Nevertheless, it has become generally accepted that the outer cell layer of the embryonic heart wall differentiates in situ to give rise to the definitive visceral epicardium (Patten, 1953).

The multiple functions of the proepicardial/epicardial cell lineage in heart development

2018 ◽  
Author(s):  
Robert Dettman ◽  
Juan Antonio Guadix ◽  
Elena Cano ◽  
Rita Carmona ◽  
Ramón Muñoz-Chápuli
Keyword(s):  
Heart Development ◽  
Epithelial Mesenchymal Transition ◽  
Cardiac Development ◽  
Cell Layer ◽  
Cell Lineage ◽  
Outer Cell ◽  
Mesenchymal Transition ◽  
Myocardial Development ◽  
Epicardial Cell ◽  
Outer Cell Layer

The epicardium is the outer cell layer of the vertebrate heart. In recent years, both the embryonic and adult epicardium have revealed unsuspected peculiarities and functions, which are essential for cardiac development. In this chapter we review the current literature on the epicardium, and describe its evolutionary origin, the mechanisms leading to the induction of its extracardiac progenitor tissue, the proepicardium, and the way in which the proepicardium is transferred to the heart to form the epicardium. We also describe the epicardial epithelial–mesenchymal transition from which mesenchymal cells originate, and the developmental fate of these cells, which contribute to the vascular, interstitial, valvular, and adipose tissue. Finally, we review the molecular interactions established between the epicardium and the myocardium, which are key for myocardial development and can also play a role in cardiac homeostasis. This chapter highlights how the epicardium has become a major protagonist in cardiac biology.

The nervous system of the neotropical millipede Gymnostreptus olivaceus Schubart, 1944 (Spirostreptida, Spirostreptidae) shows an additional cell layer

2015 ◽  
Vol 65 (2) ◽  
pp. 133-150 ◽  
Author(s):  
Annelise Francisco ◽  
Roberta C.F. Nocelli ◽  
Carmem S. Fontanetti
Keyword(s):  
Nervous System ◽  
Cell Layer ◽  
Cortical Layer ◽  
Morphological Description ◽  
Outer Cell ◽  
Olfactory Glomeruli ◽  
Additional Cell ◽  
The Central Nervous System ◽  
Inner Region ◽  
Outer Cell Layer

This study presents a morphological description of the central nervous system of the neotropical millipede Gymnostreptus olivaceus and the first report of an outer cell layer surrounding the nervous system in Diplopoda. The nervous system of this species consists of a brain formed by the fusion of proto-, deuto- and tritocerebrum, as well as a ventral nerve cord with metamerically arranged ganglia that extends through the entire length of the animal’s body. The optic lobes, mushroom bodies and olfactory glomeruli of this species were located and described. As has been reported for other millipedes, the nervous system of G. olivaceus comprises a cortical layer in which three types of neurons could be identified and an inner region of neuropil, both of which are wrapped and protected by a perineurium and a neural lamella. However, more externally to the neural lamella, there is a discontinuous and irregular outer cell sheath layer containing distinctive cells whose function appears to be linked to the nutrition and protection of neurons.

scholarly journals Induced aneuploidy disrupts MCF10A acini formation and CCND1 expression

2019 ◽  
Author(s):  
Marcel Waschow ◽  
Qi Wang ◽  
Paul Saary ◽  
Corinna Klein ◽  
Sabine Aschenbrenner ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Expression Profiling ◽  
Promoter Region ◽  
3D Model ◽  
Cell Layer ◽  
Outer Cell ◽  
Mitotic Instability ◽  
Mcf10a Cells ◽  
Outer Cell Layer ◽  
The Impact

ABSTRACTAbnormal karyotypes, namely aneuploidy, can be detected in nearly all cancer entities at different grades. The impact of these altering mutations on epigenetic regulation, especially on promoter-enhancer interactions are not well understood. Here, we applied a 3D model of MCF10A cells in a high-content screen to measure induced aneuploidy by RNA interference of 82 mitotic genes associated with aneuploidy and breast cancer. Perturbation of ESPL1 and TOP2A expression led to increased mitotic instability and subsequent aneuploidy and polylobed nuclei. During acinus formation these polylobed cells disrupted proper acinus rotation inhibiting the development of a hollow lumen and a polarized outer cell layer. Further, gene expression profiling identified upregulated CCND1 among other breast cancer related genes. We show that acquisition of aneuploidy affects the morphogenesis of MCF10A acini and expression of cancer relevant genes. By conducting 4C chromosome capturing experiments we linked the alteration of interactions of the promoter region to CCND1 upregulation.

scholarly journals Inactivation of swmA Results in the Loss of an Outer Cell Layer in a Swimming Synechococcus Strain

2005 ◽  
Vol 187 (1) ◽  
pp. 224-230 ◽  
Author(s):  
J. McCarren ◽  
J. Heuser ◽  
R. Roth ◽  
N. Yamada ◽  
M. Martone ◽  
...  
Keyword(s):  
Cell Layer ◽  
Freeze Substitution ◽  
Outer Cell ◽  
Wild Type ◽  
Gene Encoding ◽  
Unique Type ◽  
Freeze Fracturing ◽  
Additional Layer ◽  
Synechococcus Strain ◽  
Outer Cell Layer

ABSTRACT The mechanism of nonflagellar swimming of marine unicellular cyanobacteria remains poorly understood. SwmA is an abundant cell surface-associated 130-kDa glycoprotein that is required for the generation of thrust in Synechococcus sp. strain WH8102. Ultrastructural comparisons of wild-type cells to a mutant strain in which the gene encoding SwmA has been insertionally inactivated reveal that the mutant lacks a layer external to the outer membrane. Cryofixation and freeze-substitution are required for the preservation of this external layer. Freeze fracturing and etching reveal that this additional layer is an S-layer. How the S-layer might function in motility remains elusive; however, this work describes an ultrastructural component required for this unique type of swimming. In addition, the work presented here describes the envelope structure of a model swimming cyanobacterium.

scholarly journals Lack of response of INT-407 cells to the presence of non-culturableCampylobacter jejuni

2007 ◽  
Vol 136 (10) ◽  
pp. 1401-1406 ◽  
Author(s):  
L. VERHOEFF-BAKKENES ◽  
W. C. HAZELEGER ◽  
M. H. ZWIETERING ◽  
R. De JONGE
Keyword(s):  
Campylobacter Jejuni ◽  
Cell Layer ◽  
Potential Effect ◽  
Outer Cell ◽  
Culturable Bacteria ◽  
Small Intestines ◽  
Outer Cell Layer ◽  
Number Of Bacteria

SUMMARYMany contradictory articles on the infectivity of non-culturableCampylobacter jejunican be found. We studied the effect of non-culturableC. jejuniin anin vitroassay. To prevent the potential effect of a few culturable bacteria in the non-culturable suspension, INT-407 cells, which mimic the outer cell layer in the small intestines, were exposed to culturableC. jejunisuspensions with or without non-culturableC. jejuni. The number of bacteria adhering to and/or invading INT-407 cells and the IL-8 secretion were measured. No differences were found between bacterial suspensions with or without non-culturableC. jejuniadded. These findings show that non-culturableC. jejunido not adhere to or invade INT-407 cells and do not induce an immune response. As previous studies showed a correlation between the usedin vitroassays and the effectin vivo, our study strongly suggests that culturability is a good indicator of the risk forC. jejuniinfection.

scholarly journals Gene expression in visceral endoderm: a comparison of mutant and wild-type F9 embryonal carcinoma cell differentiation.

1990 ◽  
Vol 110 (5) ◽  
pp. 1767-1777 ◽  
Author(s):  
M B Rogers ◽  
S C Watkins ◽  
L J Gudas
Keyword(s):  
Embryonal Carcinoma ◽  
Cell Layer ◽  
Collagen Iv ◽  
Outer Cell ◽  
Cell Aggregates ◽  
Visceral Endoderm ◽  
Wild Type ◽  
F9 Cells ◽  
Outer Cell Layer

We have examined the abundance and cell specificity of several mRNAs that are regulated during the retinoic acid (RA)-induced differentiation of F9 embryonal carcinoma cells to visceral endoderm. The experiments confirmed the multistep nature of this process by demonstrating the expression of the ERA-1/Hox 1.6 message within 6 h after RA addition; the expression of messages specific for the extracellular matrix proteins laminin B1 and B2, and collagen IV(alpha 1) between days 4 and 12; and the expression of two visceral endoderm markers, alpha-fetoprotein (AFP) and H19, by days 8-15. In situ hybridization experiments revealed that the collagen IV(alpha 1) mRNA is restricted to the outer cell layer of F9 cell aggregates regardless of the presence or absence of RA. Laminin B1 and B2 mRNAs are concentrated in the outer cell layer of RA-treated aggregates although significant levels of message are also observed within the interior cells of the aggregates. Unexpectedly, AFP mRNA is detectable in only a subset of the outer cells of F9 cell aggregates grown 15 d in the presence of RA. The results obtained from wild-type F9 cells were compared with those from a mutant F9 cell line, RA-5-1, which was previously shown to synthesize collagen IV containing six- to ninefold less 4-hydroxyproline than that in wild-type F9 cells. RA-5-1 cells exhibit four- to sixfold less of the mRNAs encoding two visceral endoderm proteins, AFP and H19, than wild-type F9 cells after RA treatment of RA-5-1 aggregates. RA-5-1 cells, however, do exhibit an RA-associated increase in the level of ERA-1/Hox 1.6 mRNA within 6 h after adding RA. Although the collagen IV protein level is similar in wild-type F9 and RA-5-1 aggregates, the collagen IV(alpha 1) message level is 6-20-fold greater in aggregates of mutant cells than in aggregates of wild-type cells. Moreover, in situ hybridizations showed that this message is evenly distributed throughout the RA-5-1 aggregates rather than restricted to the outer cell layers as it is in wild-type F9 aggregates. These results suggest that abnormal collagen IV expression and localization are associated with decreased expression of the visceral endoderm markers, AFP and H19, in RA-5-1 cell aggregates.

Epidermis: Outer Cell Layer of the Plant

2016 ◽  
pp. 1-7 ◽  
Author(s):  
Beverley J Glover ◽  
Chiara A Airoldi ◽  
Edwige Moyroud
Keyword(s):  
Cell Layer ◽  
Outer Cell ◽  
Outer Cell Layer

scholarly journals Expression of cell adhesion molecule E-cadherin in Xenopus embryos begins at gastrulation and predominates in the ectoderm.

1989 ◽  
Vol 108 (6) ◽  
pp. 2449-2458 ◽  
Author(s):  
Y S Choi ◽  
B Gumbiner
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cell ◽  
Xenopus Laevis ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Cell Layer ◽  
Outer Cell ◽  
A6 Cells ◽  
Xenopus Embryos ◽  
E Cadherin

The expression of the Ca2+-dependent epithelial cell adhesion molecule E-cadherin (also known as uvomorulin and L-CAM) in the early stages of embryonic development of Xenopus laevis was examined. E-Cadherin was identified in the Xenopus A6 epithelial cell line by antibody cross-reactivity and several biochemical characteristics. Four independent mAbs were generated against purified Xenopus E-cadherin. All four mAbs recognized the same polypeptides in A6 cells, adult epithelial tissues, and embryos. These mAbs inhibited the formation of cell contacts between A6 cells and stained the basolateral plasma membranes of A6 cells, hepatocytes, and alveolar epithelial cells. The time of E-cadherin expression in early Xenopus embryos was determined by immunoblotting. Unlike its expression in early mouse embryos, E-cadherin was not present in the eggs or early blastula of Xenopus laevis. These findings indicate that a different Ca2+-dependent cell adhesion molecule, perhaps another member of the cadherin gene family, is responsible for the Ca2+-dependent adhesion between cleavage stage Xenopus blastomeres. Detectable accumulation of E-cadherin started just before gastrulation at stage 9 1/2 and increased rapidly up to the end of gastrulation at stage 15. In stage 15 embryos, specific immunofluorescence staining of E-cadherin was discernible only in ectoderm, but not in mesoderm and endoderm. The ectoderm at this stage consists of two cell layers. The outer cell layer of ectoderm was stained intensely, and staining was localized to the basolateral plasma membrane of these cells. Lower levels of staining were observed in the inner cell layer of ectoderm. The coincidence of E-cadherin expression with the process of gastrulation and its restriction to the ectoderm indicate that it may play a role in the morphogenetic movements of gastrulation and resulting segregation of embryonic germ layers.

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