Genetics of somatic mammalian cells. XV. Evidence for linkage between human genes for lactic dehydrogenase B and serine hydroxymethylase

1972 ◽  
Vol 80 (2) ◽  
pp. 291-297 ◽  
Author(s):  
Carol Jones ◽  
Paul Wuthier ◽  
Fa-Ten Kao ◽  
Theodore T. Puck
Keyword(s):  
Mammalian Cells ◽  
Lactic Dehydrogenase ◽  
Human Genes

scholarly journals SURFACE ANTIGENS OF MAMMALIAN CELLS AS GENETIC MARKERS. II

1973 ◽  
Vol 138 (1) ◽  
pp. 229-244 ◽  
Author(s):  
Paul Wuthier ◽  
Carol Jones ◽  
Theodore T. Puck
Keyword(s):  
Mammalian Cells ◽  
Human Lymphocytes ◽  
Human Fibroblasts ◽  
Chinese Hamster ◽  
Lactic Dehydrogenase ◽  
Hybrid Cells ◽  
Human Genes ◽  
Cultured Human Fibroblasts ◽  
Human Rbcs ◽  
Cell Plating

A second surface antigen, BL, lethal in the presence of specific antibody and complement has been identified on some human cells and shown to behave as a good genetic marker. It is autosomal, unlinked to the human AL antigen previously described, and unlinked to 15 other human genes. The AL antigen, which is linked to the lactic dehydrogenase A gene, is found on the HeLa, the cultured human fibroblast, and in small amounts on the human lymphocyte. BL occurs on HeLa cells, on cultured human fibroblasts, and on human lymphocytes, but not on human RBCs. Hybrid cells formed by fusion of human and Chinese hamster cells have been prepared containing each of the four possible combinations of these two markers. Highly selective antisera sensitive to each marker separately can be obtained. The use of single-cell plating to demonstrate the presence of the antigens and of hybrid cells containing desired combinations of the markers facilitates study in this system.

scholarly journals Orthogonal control of mean and variability of endogenous genes in a human cell line

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alain R. Bonny ◽  
João Pedro Fonseca ◽  
Jesslyn E. Park ◽  
Hana El-Samad
Keyword(s):  
Mammalian Cells ◽  
Human Cell Line ◽  
Transcriptional Level ◽  
Clear Understanding ◽  
Gene Expression Noise ◽  
Endogenous Gene ◽  
Basal Expression ◽  
Stochastic Fluctuations ◽  
Human Genes ◽  
Synthetic Circuit

AbstractStochastic fluctuations at the transcriptional level contribute to isogenic cell-to-cell heterogeneity in mammalian cell populations. However, we still have no clear understanding of the repercussions of this heterogeneity, given the lack of tools to independently control mean expression and variability of a gene. Here, we engineer a synthetic circuit to modulate mean expression and heterogeneity of transgenes and endogenous human genes. The circuit, a Tunable Noise Rheostat (TuNR), consists of a transcriptional cascade of two inducible transcriptional activators, where the output mean and variance can be modulated by two orthogonal small molecule inputs. In this fashion, different combinations of the inputs can achieve the same mean but with different population variability. With TuNR, we achieve low basal expression, over 1000-fold expression of a transgene product, and up to 7-fold induction of the endogenous gene NGFR. Importantly, for the same mean expression level, we are able to establish varying degrees of heterogeneity in expression within an isogenic population, thereby decoupling gene expression noise from its mean. TuNR is therefore a modular tool that can be used in mammalian cells to enable direct interrogation of the implications of cell-to-cell variability.

scholarly journals The Antisense Transcriptomes of Human Cells

Science ◽  
2008 ◽  
Vol 322 (5909) ◽  
pp. 1855-1857 ◽  
Author(s):  
Yiping He ◽  
Bert Vogelstein ◽  
Victor E. Velculescu ◽  
Nickolas Papadopoulos ◽  
Kenneth W. Kinzler
Keyword(s):  
Mammalian Cells ◽  
Cell Types ◽  
Human Cells ◽  
Antisense Transcripts ◽  
Genome Wide ◽  
Human Genes ◽  
A Genome ◽  
Dna Strand ◽  
The Relationship ◽  
Rna Transcript

Transcription in mammalian cells can be assessed at a genome-wide level, but it has been difficult to reliably determine whether individual transcripts are derived from the plus or minus strands of chromosomes. This distinction can be critical for understanding the relationship between known transcripts (sense) and the complementary antisense transcripts that may regulate them. Here, we describe a technique that can be used to (i) identify the DNA strand of origin for any particular RNA transcript, and (ii) quantify the number of sense and antisense transcripts from expressed genes at a global level. We examined five different human cell types and in each case found evidence for antisense transcripts in 2900 to 6400 human genes. The distribution of antisense transcripts was distinct from that of sense transcripts, was nonrandom across the genome, and differed among cell types. Antisense transcripts thus appear to be a pervasive feature of human cells, which suggests that they are a fundamental component of gene regulation.

scholarly journals Cell fitness is an omniphenotype

2018 ◽  
Author(s):  
Nicholas C. Jacobs ◽  
Ji Woong Park ◽  
Timothy R. Peterson
Keyword(s):  
Mammalian Cells ◽  
Disease Model ◽  
Environmental Variable ◽  
Cell Number ◽  
Model Organisms ◽  
Number Of Factors ◽  
Human Genes ◽  
New Gene ◽  
Altered Cell ◽  
The Cost

ABSTRACTGenotype-phenotype relationships are at the heart of biology and medicine. Numerous advances in genotyping and phenotyping have accelerated the pace of disease gene and drug discovery. Though now that there are so many genes and drugs to study, it makes prioritizing them difficult. Also, disease model assays are getting more complex and this is reflected in the growing complexity of research papers and the cost of drug development. Herein we propose a way out of this arms race. We argue for synthetic interaction testing in mammalian cells using cell fitness – which reflect changes in cell number that could be due to a number of factors – as a readout to judge the potential of a genetic or environmental variable of interest (e.g., a gene or drug). That is, if an unknown perturbation of a mammalian gene or drug of interest is combined with a known perturbation and causes a strong cell fitness phenotype relative to that caused by the known perturbation alone, this justifies proceeding with the new gene/drug in more complex models like mouse models where the known perturbation is already validated. This recommendation is backed by the following: 1) human genes essential for cell growth involve nearly all classifications of cellular and molecular processes; 2) Nearly all human genes important in cancer – a disease defined by altered cell number – are also important in other complex diseases; 3) Many drugs affect a patient’s condition and the fitness of their cells comparably. Taken together, these findings suggest cell fitness could be a broadly applicable phenotype for understanding gene and drug function. Measuring cell fitness is robust and requires little time and money. These are features that have long been capitalized on by pioneers using model organisms that we hope more mammalian biologists will recognize.

scholarly journals TuNR: Orthogonal Control of Mean and Variability of Endogenous Genes in a Human Cell Line

2020 ◽  
Author(s):  
Alain R. Bonny ◽  
João Pedro Fonseca ◽  
Jesslyn E. Park ◽  
Hana El-Samad
Keyword(s):  
Mammalian Cells ◽  
Human Cell Line ◽  
Transcriptional Level ◽  
Clear Understanding ◽  
Gene Expression Noise ◽  
Endogenous Gene ◽  
Basal Expression ◽  
Stochastic Fluctuations ◽  
Human Genes ◽  
Synthetic Circuit

AbstractStochastic fluctuations at the transcriptional level contribute to isogenic cell-to-cell heterogeneity in mammalian cell populations. However, we still have no clear understanding of the repercussions of this heterogeneity, given the lack of tools to independently control mean expression and variability of a gene. Here, we engineered a synthetic circuit to independently modulate mean expression and heterogeneity of transgenes and endogenous human genes. The circuit, a Tunable Noise Rheostat (TuNR), consists of a transcriptional cascade of two inducible transcriptional activators, where the output mean and variance can be modulated by two orthogonal small molecule inputs. In this fashion, different combinations of the inputs can achieve the same mean but with different population variability. With TuNR, we achieve low basal expression, over 1000-fold expression of a transgene product, and up to 7-fold induction of the endogenous gene NGFR. Importantly, for the same mean expression level, we are able to establish varying degrees of heterogeneity in expression within an isogenic population, thereby decoupling gene expression noise from its mean. TuNR is therefore a modular tool that can be used in mammalian cells to enable direct interrogation of the implications of cell-to-cell variability.

Chromosomal localization of human genes required for G1 progression in mammalian cells

Genomics ◽  
1989 ◽  
Vol 4 (3) ◽  
pp. 240-245 ◽  
Author(s):  
Angela Greco ◽  
Michael Ittmann ◽  
Cosimo Barletta ◽  
Claudio Basilico ◽  
Carlo M. Croce ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Chromosomal Localization ◽  
Human Genes

scholarly journals Control of mitochondrial morphology by a human mitofusin

2001 ◽  
Vol 114 (5) ◽  
pp. 867-874 ◽  
Author(s):  
A. Santel ◽  
M.T. Fuller
Keyword(s):  
Mammalian Cells ◽  
Transmembrane Domain ◽  
Mitochondrial Fission ◽  
Mitochondrial Fusion ◽  
Mitochondrial Morphology ◽  
Hydrophobic Residues ◽  
Culture Cells ◽  
Human Genes ◽  
Genes Encoding ◽  
Drosophila Protein

Although changes in mitochondrial size and arrangement accompany both cellular differentiation and human disease, the mechanisms that mediate mitochondrial fusion, fission and morphogenesis in mammalian cells are not understood. We have identified two human genes encoding potential mediators of mitochondrial fusion. The mitofusins (Mfn1 and Mfn2) are homologs of the Drosophila protein fuzzy onion (Fzo) that associate with mitochondria and alter mitochondrial morphology when expressed by transient transfection in tissue culture cells. An internal region including a predicted bipartite transmembrane domain (TM) is sufficient to target Mfn2 to mitochondria and requires hydrophobic residues within the TM. Co-expression of Mfn2 with a dominant interfering mutant dynamin-related protein (Drp1(K38A)) proposed to block mitochondrial fission resulted in long mitochondrial filaments and networks. Formation of mitochondrial filaments and networks required a wild-type Mfn2 GTPase domain, suggesting that the Mfn2 GTPase regulates or mediates mitochondrial fusion and that mitofusins and dynamin related GTPases play opposing roles in mitochondrial fusion and fission in mammals, as in yeast.

Ultrastructural Alterations in Hela Cells Induced by Spider Venom

1967 ◽  
Vol 25 ◽  
pp. 20-21
Author(s):  
Dale E. McClendon ◽  
Paul N. Morgan ◽  
Bernard L. Soloff
Keyword(s):  
Growth Medium ◽  
Mammalian Cells ◽  
Carcinoma Cells ◽  
Venom Protein ◽  
Sterile Saline ◽  
Carbon Coated ◽  
Available Information ◽  
Loxosceles Reclusa ◽  
Essential Growth ◽  
Solution Cultures

It has been observed that minute amounts of venom from the brown recluse spider, Loxosceles reclusa, are capable of producing cytotoxic changes in cultures of certain mammalian cells (Morgan and Felton, 1965). Since there is little available information concerning the effect of venoms on susceptible cells, we have attempted to characterize, at the electron microscope level, the cytotoxic changes produced by the venom of this spider.Cultures of human epithelial carcinoma cells, strain HeLa, were initiated on sterile, carbon coated coverslips contained in Leighton tubes. Each culture was seeded with approximately 1x105 cells contained in 1.5 ml of a modified Eagle's minimum essential growth medium prepared in Hank's balanced salt solution. Cultures were incubated at 36° C. for three days prior to the addition of venom. The venom was collected from female brown recluse spiders and diluted in sterile saline. Protein determinations on the venom-were made according to the spectrophotometric method of Waddell (1956). Approximately 10 μg venom protein per ml of fresh medium was added to each culture after discarding the old growth medium. Control cultures were treated similarly, except that no venom was added. All cultures were reincubated at 36° C.

Use of Uranium-Labeled Antibodies for Electron Microscopic Localization of Various Antigens in Mammalian Cells

1967 ◽  
Vol 25 ◽  
pp. 136-137
Author(s):  
J. P. Petrali ◽  
E. J. Donati ◽  
L. A. Sternberger
Keyword(s):  
Endoplasmic Reticulum ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Specific Antiserum ◽  
Electron Microscopic ◽  
E Coli ◽  
Cytoplasmic Membranes ◽  
Viral Progeny ◽  
Ultrathin Sections ◽  
Electron Microscopic Localization

Specific contrast is conferred to subcellular antigen by applying purified antibodies, exhaustively labeled with uranium under immunospecific protection, to ultrathin sections. Use of Seligman’s principle of bridging osmium to metal via thiocarbohydrazide (TCH) intensifies specific contrast. Ultrathin sections of osmium-fixed materials were stained on the grid by application of 1) thiosemicarbazide (TSC), 2) unlabeled specific antiserum, 3) uranium-labeled anti-antibody and 4) TCH followed by reosmication. Antigens to be localized consisted of vaccinia antigen in infected HeLa cells, lysozyme in monocytes of patients with monocytic or monomyelocytic leukemia, and fibrinogen in the platelets of these leukemic patients. Control sections were stained with non-specific antiserum (E. coli).In the vaccinia-HeLa system, antigen was localized from 1 to 3 hours following infection, and was confined to degrading virus, the inner walls of numerous organelles, and other structures in cytoplasmic foci. Surrounding architecture and cellular mitochondria were unstained. 8 to 14 hours after infection, antigen was localized on the outer walls of the viral progeny, on cytoplasmic membranes, and free in the cytoplasm. Staining of endoplasmic reticulum was intense and focal early, and weak and diffuse late in infection.

Ultrastructural Changes in Three Different Mammalian Cells Following Ultraviolet Laser Irradiation

1972 ◽  
Vol 30 ◽  
pp. 350-351
Author(s):  
K. Shankar Narayan ◽  
Kailash C. Gupta ◽  
Tohru Okigaki
Keyword(s):  
Ultraviolet Light ◽  
Mammalian Cells ◽  
Biological Effects ◽  
Survival Rates ◽  
Chinese Hamster ◽  
Cell Types ◽  
Differential Sensitivity ◽  
Ultrastructural Changes ◽  
Ultraviolet Laser

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.

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