Regulation of nuclear size in mammalian embryos

2014 ◽  
Author(s):  
Elina Tsichlaki ◽  
Greg Fitzharris
Author(s):  
Patricia G. Calarco ◽  
Margaret C. Siebert

Visualization of preimplantation mammalian embryos by electron microscopy is difficult due to the large size of the ircells, their relative lack of internal structure, and their highly hydrated cytoplasm. For example, the fertilized egg of the mouse is a single cell of approximately 75μ in diameter with little organized cytoskelet on and apaucity ofor ganelles such as endoplasmic reticulum (ER) and Golgi material. Thus, techniques that work well on tissues or cell lines are often not adaptable to embryos at either the LM or EM level.Over several years we have perfected techniques for visualization of mammalian embryos by LM and TEM, SEM and for the pre-embedding localization of antigens. Post-embedding antigenlocalization in thin sections of mouse oocytes and embryos has presented a more difficult challenge and has been explored in LR White, LR Gold, soft EPON (after etching of sections), and Lowicryl K4M. To date, antigen localization has only been achieved in Lowicryl-embedded material, although even with polymerization at-40°C, the small ER vesicles characteristic of embryos are unrecognizable.


1991 ◽  
Vol 19 (1) ◽  
pp. 41-47
Author(s):  
Renato Rizzi ◽  
Francesco Re ◽  
Enzo Chiesara

It has been observed that cells often respond to carcinogens by nuclear enlargement. For this reason, new morphometric approaches have been developed to evaluate cell modifications in pre-carcinogenesis assays. Morphometric computerised automatic analysis, with original software, was performed on HeLa cells treated with various compounds (hydroxyurea, dimethylnitrosamine, N-methyl- N’-nitro-nitrosoguanidine and cyclophosphamide) to evaluate nuclear size changes.


2021 ◽  
Author(s):  
Pallavi Deolal ◽  
Gurranna Male ◽  
Krishnaveni Mishra
Keyword(s):  

2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Jens Popken ◽  
Maik Dahlhoff ◽  
Tuna Guengoer ◽  
Eckhard Wolf ◽  
Valeri Zakhartchenko

1995 ◽  
Vol 218 (1) ◽  
pp. 114-122 ◽  
Author(s):  
Gustavo R. Rosania ◽  
Joel A. Swanson

1995 ◽  
Vol 73 (10) ◽  
pp. 1951-1959 ◽  
Author(s):  
Charles H. Jagoe ◽  
Dave A. Welter

Chromosome number and genomic DNA content vary widely among fish species, and ploidy can vary within species. This suggests that the size, shape, and morphological features of cell nuclei may also vary. Nucleated erythrocytes of fish are an easily sampled homogeneous population of differentiated cells ideal for inter- and intra-species comparisons. We collected blood samples from largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus), chain pickerel (Esox niger), yellow perch (Perca flavescens), mosquitofish (Gambusia holbrooki), redeye bass (Micropterus coosae), and rainbow trout (Oncorhynchus mykiss) and removed cytoplasm and nuclear membranes from blood cells. Individual nuclei were examined and measured using scanning electron microscopy and a computerized image analysis system, and inter- and intra-species differences evaluated by nested analysis of variance. Nuclear size and shape varied significantly among species. Isolated nuclei had conspicuous apertures or holes, and the number and size of these holes also varied significantly among species. Variations in nuclear size and structure within species were small compared with interspecies differences. Little is known of the ultrastructure of erythrocyte nuclei in lower vertebrates, but their structure differs considerably from that of other vertebrate non-erythroid cells, suggesting that the organization of their DNA and associated proteins may be different.


1989 ◽  
Vol 19 (1-2) ◽  
pp. 117-129 ◽  
Author(s):  
A. Massip ◽  
P. Van Der Zwalmen ◽  
B. Scheffen ◽  
F. Ectors
Keyword(s):  

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