Spatial epigenetics: linking nuclear structure and function in higher eukaryotes

2010 ◽  
Vol 48 ◽  
pp. 25-43 ◽  
Author(s):  
Dean A. Jackson

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’.

2021 ◽  
pp. 1-10
Author(s):  
Rumeysa Tutar ◽  
Betül Çelebi-Saltik

The placenta is the main organ that allows the fertilized oocyte to develop and mature. It allows the fetus to grow in the prenatal period by transferring oxygen and nutrients between the mother and the fetus. It acts as a basic endocrine organ which creates the physiological changes related to pregnancy and birth in the mother. Removal of wastes and carbon dioxide from the fetus is also achieved by the placenta. It prevents the rejection of the fetus and protects the fetus from harmful effects. Research on the human placenta focuses on understanding the placental structure and function to illuminate the complex structure of this important organ with technological advances. The structure and function of the placental barrier have been investigated with in vitro studies in 2D/3D, and various results have been published comparatively. In this review, we introduce the nature of the placenta with its 3D composition which has been called niche. Different cell types and placental structures are presented. We describe the systems and approaches used in the creation of current 3D placenta, placental transfer models as 3D placental barriers, and micro-engineered 3D placenta on-a-chip to explore complicated placental responses to nanoparticle exposure.


1989 ◽  
Vol 37 (2) ◽  
pp. 165-172 ◽  
Author(s):  
G Bennett ◽  
R Hemming

Sections of bullfrog dorsal root ganglia were analyzed for cytidine monophosphatase (CMPase), thiamine pyrophosphatase (TPPase), and nicotinamide adenine dinucleotide phosphatase (NADPase) activity, and the distributions of these enzymatic activities were compared with those traditionally found in other cell types (e.g., CMPase: Golgi trans-sacculotubular network; TPPase: trans-Golgi saccule(s); NADPase: intermediate Golgi saccules). In the present study, CMPase activity in neurons was localized mainly to the Golgi trans-sacculotubular network and lysosomes, but sometimes also occurred at the ends of the trans and most distal intermediate Golgi saccules. A similar distribution was found in satellite and Schwann cells. TPPase activity in neurons occurred not only in the trans-Golgi saccule but also in the trans-sacculotubular network, lysosomes, and scattered tubular elements. In satellite and Schwann cells, activity was found in both the trans saccule and trans-sacculotubular network, and substantial activity often appeared in the more distal of the intermediate saccules. NADPase activity in neurons was usually absent from the intermediate Golgi saccules and was confined to the trans-sacculotubular network and lysosomes; however, activity was sometimes also found in the intermediate and/or trans-Golgi saccules. In satellite and Schwann cells, activity appeared consistently in both the trans-sacculotubular network and intermediate saccules, as well as in lysosomes. These distributions, especially in the case of TPPase and NADPase, differ substantially from the most frequently reported localizations of the above enzymes, indicating that the Golgi complex may exhibit considerable plasticity of structure and function in different cell types.


Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2507
Author(s):  
Carla Mucignat-Caretta

The brain may be affected by a variety of tumors of different grade, which originate from different cell types at distinct locations, thus impacting on the brain structure and function [...]


STEMedicine ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. e9
Author(s):  
Cenfeng Chu ◽  
Guisheng Zhong ◽  
Hui Li

Cytoskeleton plays an essential role in many functions in different cells and has been involved in the pathogenesis of many neural diseases. With the development of super-resolution fluorescence imaging technologies, which combine the molecular specificity and simple sample preparation of fluorescence microscopy and provide a spatial resolution comparable to that of electron microscopy, numerous new features have been revealed in the cytoskeletal organization of the subcortical cytoskeleton. A novel periodic lattice cytoskeleton is prevalent in different cell types throughout the nervous system. Here, we review the current studies of the molecular distribution, developmental mechanisms, and functional properties of the periodic cytoskeleton structure.


Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 622-640 ◽  
Author(s):  
J. B. Gurdon

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.


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