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.

The cloning cycle: from amphibia to mammals and back

2001 ◽  
Vol 9 (1) ◽  
pp. 3-31 ◽  
Author(s):  
IM Lewis ◽  
MJ Munsie ◽  
AJ French ◽  
R Daniels ◽  
AO Trounson
Keyword(s):  
Developmental Biology ◽  
Nuclear Transfer ◽  
Cellular Differentiation ◽  
Cell Types ◽  
Nuclear Material ◽  
Laboratory Animals ◽  
Cell Type ◽  
Differentiated Cells ◽  
Different Cell Types ◽  
Fertilized Egg

The process whereby a fertilized egg develops into more than 200 different cell types and forms a new individual is both intriguing and fundamental to developmental biology. The systematic pathway of cellular differentiation is generally thought to confer a restriction whereby differentiated cells lose the capacity to change into other cell types. However, the substitution of nuclear material from one cell type (egg) with that of another, in a process known as nuclear transfer or cloning, can reverse this restriction by removing epigenetic modifications to the chromatin structure. The ability to clone new individuals using this procedure was achieved some 30 years ago in amphibia in an effort to understand cellular differentiation. More recently, with the advent of improved embryo micromanipulation techniques, the technology has been applied to domestic and laboratory animals.

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 A conserved expression signature predicts growth rate and reveals cell & lineage-specific differences

2019 ◽  
Author(s):  
Zhisheng Jiang ◽  
Serena Francesca Generoso ◽  
Marta Badia ◽  
Bernhard Payer ◽  
Lucas B. Carey
Keyword(s):  
Cell Lineage ◽  
Gene Expression Signature ◽  
Cell Types ◽  
Eukaryotic Cell ◽  
Rna Seq ◽  
Cell Type Specificity ◽  
Expression Signature ◽  
Differentiated Cells ◽  
Different Cell Types ◽  
High Degree

By performing RNA-seq on cells FACS sorted by their proliferation rate, this study identifies a gene expression signature capable of predicting proliferation rates in diverse eukaryotic cell types and species. This signature, applied to scRNAseq data from C.elegans, reveals lineage-specific differences in proliferation during development. In contrast to the universality of the proliferation signature, mitochondria and metabolism related genes show a high degree of cell-type specificity; mouse pluripotent stem cells (mESCs) and differentiated cells (fibroblasts) exhibit opposite relations between mitochondria state and proliferation. Furthermore, we identified a slow proliferating subpopulation of mESCs with higher expression of pluripotency genes. Finally, we show that fast and slow proliferating subpopulations are differentially sensitive to mitochondria inhibitory drugs in different cell types.

scholarly journals Exploratory analysis of transposable elements expression in the C. elegans early embryo

2019 ◽  
Vol 20 (S9) ◽  
Author(s):  
Federico Ansaloni ◽  
Margherita Scarpato ◽  
Elia Di Schiavi ◽  
Stefano Gustincich ◽  
Remo Sanges
Keyword(s):  
Nervous System ◽  
Transposable Elements ◽  
Embryo Development ◽  
Cell Types ◽  
Early Embryo ◽  
Bioinformatics Pipeline ◽  
Early Embryo Development ◽  
C Elegans ◽  
Differentiated Cells ◽  
Different Cell Types

Abstract Background Transposable Elements (TE) are mobile sequences that make up large portions of eukaryote genomes. The functions they play within the complex cellular architecture are still not clearly understood, but it is becoming evident that TE have a role in several physiological and pathological processes. In particular, it has been shown that TE transcription is necessary for the correct development of mice embryos and that their expression is able to finely modulate transcription of coding and non-coding genes. Moreover, their activity in the central nervous system (CNS) and other tissues has been correlated with the creation of somatic mosaicisms and with pathologies such as neurodevelopmental and neurodegenerative diseases as well as cancers. Results We analyzed TE expression among different cell types of the Caenorhabditis elegans (C. elegans) early embryo asking if, where and when TE are expressed and whether their expression is correlated with genes playing a role in early embryo development. To answer these questions, we took advantage of a public C. elegans embryonic single-cell RNA-seq (sc-RNAseq) dataset and developed a bioinformatics pipeline able to quantify reads mapping specifically against TE, avoiding counting reads mapping on TE fragments embedded in coding/non-coding transcripts. Our results suggest that i) canonical TE expression analysis tools, which do not discard reads mapping on TE fragments embedded in annotated transcripts, may over-estimate TE expression levels, ii) Long Terminal Repeats (LTR) elements are mostly expressed in undifferentiated cells and might play a role in pluripotency maintenance and activation of the innate immune response, iii) non-LTR are expressed in differentiated cells, in particular in neurons and nervous system-associated tissues, and iv) DNA TE are homogenously expressed throughout the C. elegans early embryo development. Conclusions TE expression appears finely modulated in the C. elegans early embryo and different TE classes are expressed in different cell types and stages, suggesting that TE might play diverse functions during early embryo development.

scholarly journals The Tuberculous Granuloma: An Unsuccessful Host Defence Mechanism Providing a Safety Shelter for the Bacteria?

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Mayra Silva Miranda ◽  
Adrien Breiman ◽  
Sophie Allain ◽  
Florence Deknuydt ◽  
Frederic Altare
Keyword(s):  
Cell Types ◽  
Giant Cells ◽  
The Body ◽  
Differentiated Cells ◽  
Latently Infected ◽  
Long Time ◽  
Infectious Stage ◽  
Different Cell Types

One of the main features of the immune response toM. Tuberculosisis the formation of an organized structure called granuloma. It consists mainly in the recruitment at the infectious stage of macrophages, highly differentiated cells such as multinucleated giant cells, epithelioid cells and Foamy cells, all these cells being surrounded by a rim of lymphocytes. Although in the first instance the granuloma acts to constrain the infection, some bacilli can actually survive inside these structures for a long time in a dormant state. For some reasons, which are still unclear, the bacilli will reactivate in 10% of the latently infected individuals, escape the granuloma and spread throughout the body, thus giving rise to clinical disease, and are finally disseminated throughout the environment. In this review we examine the process leading to the formation of the granulomatous structures and the different cell types that have been shown to be part of this inflammatory reaction. We also discuss the differentin vivoandin vitromodels available to study this fascinating immune structure.

Spatial epigenetics: linking nuclear structure and function in higher eukaryotes

2010 ◽  
Vol 48 ◽  
pp. 25-43 ◽  
Author(s):  
Dean A. Jackson
Keyword(s):  
Nuclear Structure ◽  
Genetic Information ◽  
Nuclear Architecture ◽  
Cell Types ◽  
Structure And Function ◽  
Chromatin Dynamics ◽  
Functional Product ◽  
Higher Eukaryotes ◽  
And Function ◽  
Different Cell Types

Eukaryotic cells are defined by the genetic information that is stored in their DNA. To function, this genetic information must be decoded. In doing this, the information encoded in DNA is copied first into RNA, during RNA transcription. Primary RNA transcripts are generated within transcription factories, where they are also processed into mature mRNAs, which then pass to the cytoplasm. In the cytoplasm these mRNAs can finally be translated into protein in order to express the genetic information as a functional product. With only rare exceptions, the cells of an individual multicellular eukaryote contain identical genetic information. However, as different genes must be expressed in different cell types to define the structure and function of individual tissues, it is clear that mechanisms must have evolved to regulate gene expression. In higher eukaryotes, mechanisms that regulate the interaction of DNA with the sites where nuclear functions are performed provide one such layer of regulation. In this chapter, I evaluate how a detailed understanding of nuclear structure and chromatin dynamics are beginning to reveal how spatial mechanisms link chromatin structure and function. As these mechanisms operate to modulate the genetic information in DNA, the regulation of chromatin function by nuclear architecture defines the concept of ‘spatial epigenetics’.

scholarly journals Előprogramozott gének

2017 ◽  
Vol 158 (34) ◽  
pp. 1323-1330
Author(s):  
János Szabad
Keyword(s):  
Gene Expression ◽  
Genetic Information ◽  
Cell Types ◽  
Epigenetic Mechanisms ◽  
Base Pairs ◽  
Control Gene Expression ◽  
Protein Molecules ◽  
Chromatin Compactness ◽  
The Right ◽  
Different Cell Types

Abstract: Cells feel good and carry on perfect functions when they contain the right types of proteins in the right concentration, at the right time and sites. There are mechanisms that ensure the right level of gene expression in the different cell types: the formation of protein molecules based on the DNA-encoded genetic information. Gene expression can also be regulated through the compactness of chromatin, i.e. the accessibility of the genes. The chromosomes are repositories of the genetic information – the sequence of base pairs – and also of the so-called epigenetic mechanisms that control gene expression through the regulation of chromatin compactness. The epigenetic mechanisms operate through DNA methylation and/or the regulation of chromatin compactness. The present overview takes a look into the phenomenon of epigenesis. It summarizes how genetic crosses reveal the involvement of epigenesis, explains its meaning and impact on life of the organisms. An understanding of epigenesis provides guidance to improve our life. Orv Hetil. 2017; 158(34): 1323–1330.

scholarly journals The Developmental Capacity of Nuclei Taken from Differentiating Endoderm Cells of Xenopus laevis

Development ◽  
1960 ◽  
Vol 8 (4) ◽  
pp. 505-526
Author(s):  
J. B. Gurdon
Keyword(s):  
Xenopus Laevis ◽  
Rana Pipiens ◽  
Nuclear Transplantation ◽  
Blastula Stage ◽  
Developmental Capacity ◽  
Nuclear Changes ◽  
Nuclear Differentiation ◽  
Development Proceeds ◽  
Transplantation Experiments ◽  
Different Parts

An important question concerning embryonic differentiation is whether the nuclei of somatic cells in different parts of an embryo come to differ genetically from each other during development. It has become possible to investigate this matter since King & Briggs (1955) have shown that nuclear transplantation is a satisfactory technique for testing the developmental potentialities of embryonic nuclei. These authors (1957, 1960) have used Rana pipiens for transplantation experiments with endoderm nuclei, and have found that these nuclei become progressively limited in their developmental capacity after the late blastula stage. This paper describes some similar experiments carried out with endoderm nuclei of Xenopus laevis. The general conclusion that nuclei change as development proceeds is confirmed; there are, however, considerable differences between Rana and Xenopus in the rate and time of onset of nuclear changes. These differences make it easier to understand the significance of nuclear differentiation during embryonic development.

scholarly journals Independently paced calcium oscillations in progenitor and differentiated cells in an ex vivo epithelial organ

2021 ◽  
Author(s):  
Anna Kim ◽  
Amanda Nguyen ◽  
Marco Marchetti ◽  
Denise Montell ◽  
Beth Pruitt ◽  
...  
Keyword(s):  
Stem Cells ◽  
Ex Vivo ◽  
Cell Types ◽  
Cytosolic Calcium ◽  
Calcium Oscillations ◽  
Enteroendocrine Cells ◽  
Calcium Dynamics ◽  
Differentiated Cells ◽  
Different Cell Types

Cytosolic calcium is a highly dynamic, tightly regulated, and broadly conserved cellular signal. Calcium dynamics have been studied widely in cellular monocultures, yet in vivo most organs comprise heterogeneous populations of stem and differentiated cells. We examined calcium dynamics in each cell type of the adult Drosophila intestine, a self-renewing epithelial organ where multipotent stem cells give rise to mature absorptive enterocytes and secretory enteroendocrine cells. Here we perform live imaging of whole organs ex vivo, and we employ orthogonal expression of red and green calcium sensors to determine whether calcium oscillations between different cell types are coupled. We show that stem cell daughters adopt strikingly distinct patterns of calcium oscillations when they acquire their terminal fates: enteroendocrine cells exhibit single-cell calcium oscillations, while long-range calcium waves propagate rhythmically across large fields of enterocytes. These multicellular waves do not propagate through progenitor cells (stem cells and undifferentiated enterocyte precursors), whose oscillation frequency is approximately half that of enteroendocrine cells. Organ-scale inhibition of gap junctions eliminates calcium oscillations in all three cell types, even, intriguingly, in progenitor and enteroendocrine cells that are surrounded only by enterocytes. Our findings establish that cells adopt fate-specific modes of calcium dynamics as they terminally differentiate and reveal that the oscillatory dynamics of different cell types in the same epithelium are paced independently.

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