scholarly journals Unstable and stable CAD gene amplification: importance of flanking sequences and nuclear environment in gene amplification.

1987 ◽  
Vol 7 (4) ◽  
pp. 1415-1424 ◽  
Author(s):  
J Meinkoth ◽  
A M Killary ◽  
R E Fournier ◽  
G M Wahl
Keyword(s):  
Mouse Chromosome ◽  
Gene Amplification ◽  
Mouse Cell ◽  
Cad Gene ◽  
Flanking Sequences ◽  
Mouse Cells ◽  
Nuclear Environment ◽  
Stable Cad ◽  
First Time ◽  
Degree Of Instability

We analyzed the amplification of the CAD gene in independently isolated N-(phosphonacetyl)-L-aspartate-resistant clones derived from single parental clones in two mouse cell lines. We report for the first time that the CAD gene is amplified unstably in mouse cells, that the degree of instability varies greatly between clones, and that minute chromosomes and highly unstable chromosomelike structures contain the amplified sequences. These data are most consistent with the idea that the amplified unit in each clone consists of different flanking DNA and that such differences engender amplified sequences with unequal stability. We also introduced the mouse chromosome containing the CAD gene into hamster cells by microcell-mediated chromosome transfer to determine whether the propensity for unstable extrachromosomal amplification of the mouse CAD gene would prevail in the hamster cell nuclear environment. We report that the mouse CAD gene was amplified stably in expanded chromosomal regions in each of seven hybrids that were analyzed. This observation is consistent with the idea that the nuclear environment influences whether mutants containing intra- or extrachromosomally amplified sequences will be isolated.

Unstable and stable CAD gene amplification: importance of flanking sequences and nuclear environment in gene amplification

1987 ◽  
Vol 7 (4) ◽  
pp. 1415-1424
Author(s):  
J Meinkoth ◽  
A M Killary ◽  
R E Fournier ◽  
G M Wahl
Keyword(s):  
Mouse Chromosome ◽  
Gene Amplification ◽  
Mouse Cell ◽  
Cad Gene ◽  
Flanking Sequences ◽  
Mouse Cells ◽  
Nuclear Environment ◽  
Stable Cad ◽  
First Time ◽  
Degree Of Instability

We analyzed the amplification of the CAD gene in independently isolated N-(phosphonacetyl)-L-aspartate-resistant clones derived from single parental clones in two mouse cell lines. We report for the first time that the CAD gene is amplified unstably in mouse cells, that the degree of instability varies greatly between clones, and that minute chromosomes and highly unstable chromosomelike structures contain the amplified sequences. These data are most consistent with the idea that the amplified unit in each clone consists of different flanking DNA and that such differences engender amplified sequences with unequal stability. We also introduced the mouse chromosome containing the CAD gene into hamster cells by microcell-mediated chromosome transfer to determine whether the propensity for unstable extrachromosomal amplification of the mouse CAD gene would prevail in the hamster cell nuclear environment. We report that the mouse CAD gene was amplified stably in expanded chromosomal regions in each of seven hybrids that were analyzed. This observation is consistent with the idea that the nuclear environment influences whether mutants containing intra- or extrachromosomally amplified sequences will be isolated.

Analysis of CAD Gene Amplification Using a Combined Approach of Molecular Genetics and Cytogenetics

1984 ◽  
pp. 319-345 ◽  
Author(s):  
Geoffrey M. Wahl ◽  
Virginia Allen ◽  
Suzanne Delbruck ◽  
Walter Eckhart ◽  
Judy Meinkoth ◽  
...  
Keyword(s):  
Molecular Genetics ◽  
Gene Amplification ◽  
Combined Approach ◽  
Cad Gene

scholarly journals Cytotoxic effect of Aeruginosin-865, capsaicin, and resveratrol on mouse cell lines of different origin

2021 ◽  
Vol 90 (3) ◽  
pp. 307-314
Author(s):  
Ivana Veselá ◽  
Jose Cheel ◽  
Jaroslava Tomenendálová ◽  
Pavla Hamouzová ◽  
Pavel Hrouzek ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cytotoxic Effect ◽  
Mouse Cell ◽  
Tumour Cells ◽  
Normal Cells ◽  
Hepatotoxic Effect ◽  
Anticancer Treatment ◽  
Mouse Cells ◽  
Different Origin ◽  
Anticancer Drug Development

The aim of the study was to compare the effects of three natural bioactive compounds (and their combinations) on normal vs. tumour-transformed mouse cells. The cytotoxic effect of Aeruginosin-865 (Aer), capsaicin (Cap), resveratrol (Res) and their combinations was evaluated on normal hepatocytes (AML) and tumour cells derived from livers (Hepa) and kidneys (Renca). Various concentrations from 25 to 200 μM of tested substances were used. Only the Aer + Res combination and a low concentration of Res had a significant cytotoxic effect on Hepa and Renca and no significant cytotoxic effect on AML. Cap had a significant cytotoxic effect on all tested cell lines, but tumour-derived cells showed higher resistance than AML. A significantly increased cytotoxicity was found in the combination of Cap + Res compared to each substance alone. All types of cells showed similar sensitivity to the cytotoxic effect of Cap + Res. Because of a possible hepatotoxic effect, we recommend further investigations into side-effects of Cap + Res. No cytotoxic effect was described in Cap + Aer or in Aer alone. Only substances with a significant cytotoxic effect on tumour cells and no cytotoxic effect on normal cells can be potentially used in anticancer treatment. According to the results, only Res or the combination of Aer + Res can be recommended for further evaluation in the process of new anticancer drug development. The potential hepatotoxic effect of Cap + Res can significantly limit the utilisation of these substances in anticancer treatment.

Gene amplification in methotrexate-resistant mouse cells

1981 ◽  
Vol 153 (2) ◽  
pp. 219-236 ◽  
Author(s):  
Christopher J. Bostock ◽  
Christopher Tyler-Smith
Keyword(s):  
Gene Amplification ◽  
Resistant Mouse ◽  
Mouse Cells

scholarly journals Structure of DNA formed in the first step of CAD gene amplification.

1986 ◽  
Vol 5 (9) ◽  
pp. 2115-2121 ◽  
Author(s):  
E. Giulotto ◽  
I. Saito ◽  
G.R. Stark
Keyword(s):  
Gene Amplification ◽  
Cad Gene

Induction of CAD gene amplification by restriction endonucleases in V79,B7 Chinese hamster cells

1989 ◽  
Vol 225 (1-2) ◽  
pp. 61-64 ◽  
Author(s):  
P. Cavolina ◽  
C. Agnese ◽  
A. Maddalena ◽  
G. Sciandrello ◽  
A. Di Leonardo
Keyword(s):  
Gene Amplification ◽  
Chinese Hamster ◽  
Restriction Endonucleases ◽  
Chinese Hamster Cells ◽  
Cad Gene

scholarly journals Comparison of Gamma Interferon-Mediated Antichlamydial Defense Mechanisms in Human and Mouse Cells

2006 ◽  
Vol 74 (1) ◽  
pp. 225-238 ◽  
Author(s):  
Christine Roshick ◽  
Heidi Wood ◽  
Harlan D. Caldwell ◽  
Grant McClarty
Keyword(s):  
Nitric Oxide ◽  
Cell Lines ◽  
Human Cell ◽  
Mouse Cell ◽  
Gamma Interferon ◽  
Host Cells ◽  
Human Cell Lines ◽  
Mouse Cells ◽  
Ifn Γ ◽  
Human And Mouse

ABSTRACT Gamma interferon (IFN-γ)-induced effector mechanisms have potent antichlamydial activities that are critical to host defense. The most prominent and well-studied effectors are indoleamine dioxygenase (IDO) and nitric oxide (NO) synthase. The relative contributions of these mechanisms as inhibitors of chlamydial in vitro growth have been extensively studied using different host cells, induction mechanisms, and chlamydial strains with conflicting results. Here, we have undertaken a comparative analysis of cytokine- and lipopolysaccharide (LPS)-induced IDO and NO using an extensive assortment of human and murine host cells infected with human and murine chlamydial strains. Following cytokine (IFN-γ or tumor necrosis factor alpha) and/or LPS treatment, the majority of human cell lines induced IDO but failed to produce NO. Conversely, the majority of mouse cell lines studied produced NO, not IDO. Induction of IDO in human cell lines inhibited growth of L2 and mouse pneumonitis agent, now referred to as Chlamydia muridarum MoPn equally in all but two lines, and inhibition was completely reversible by the addition of tryptophan. IFN-γ treatment of mouse cell lines resulted in substantially greater reduction of L2 than MoPn growth. However, despite elevated NO production by murine cells, blockage of NO synthesis with the l-arginine analogue N-monomethyl-l-arginine only partially rescued chlamydial growth, suggesting the presence of another IFN-γ-inducible antichlamydial mechanism unique to murine cells. Moreover, NO generated from the chemical nitric oxide donor sodium nitroprusside showed little direct effect on chlamydial infectivity or growth, indicating a natural resistance to NO. Finally, IFN-γ-inducible IDO expression in human HeLa cells was inhibited following exogenous NO treatment, resulting in a permissive environment for chlamydial growth. In summary, cytokine- and LPS-inducible effectors produced by human and mouse cells differ and, importantly, these host-specific effector responses result in chlamydial strain-specific antimicrobial activities.

scholarly journals Functional analysis of elements affecting expression of the beta-actin gene of carp.

1990 ◽  
Vol 10 (7) ◽  
pp. 3432-3440 ◽  
Author(s):  
Z J Liu ◽  
B Moav ◽  
A J Faras ◽  
K S Guise ◽  
A R Kapuscinski ◽  
...  
Keyword(s):  
Regulatory Region ◽  
Housekeeping Genes ◽  
Initiation Site ◽  
Proximal Promoter ◽  
Actin Gene ◽  
Base Pairs ◽  
First Intron ◽  
Beta Actin ◽  
Flanking Sequences ◽  
Mouse Cells

Regulatory regions of the beta-actin gene of the common carp (Cyprinus carpio) have been examined by linking upstream, 5'-flanking sequences and regions of the first intron to a bacterial chloramphenicol acetyltransferase (CAT) reporter gene. By analysis of the mRNA products and encoded CAT activity, we have identified four putative regions that influence expression: (i) a negative regulatory region 2,300 to 1,100 base pairs (bp) ahead of the gene; (ii) a proximal promoter element, containing the highly conserved CCAAT, CC(A/T)6GG, and TATA boxes, that is within the first 204 bp upstream of the initiation site; (iii) a negative element of 426 bp in the 5' region of the first intron; and (iv) a positive 304-bp element near the end of the first intron that contains highly conserved sequences found in all characterized beta-actin genes. The positive intron element is not a classical enhancer; it is position and orientation dependent, as has been observed in other housekeeping genes in vertebrates. Depending on the elements joined together, CAT gene expression can be modulated more than 500-fold in transfected mouse cells.

Chromosome rearrangements associated with CAD gene amplification. Experiments with cell hybrids

1992 ◽  
Vol 265 (1) ◽  
pp. 9-21 ◽  
Author(s):  
Silvia Viaggi ◽  
Michael Nüsse ◽  
Laura Ottaggio ◽  
Stefania Bonatti
Keyword(s):  
Gene Amplification ◽  
Chromosome Rearrangements ◽  
Cell Hybrids ◽  
Cad Gene

scholarly journals Genome organization of the Chelonus inanitus polydnavirus: excision sites, spacers and abundance of proviral and excised segments

2007 ◽  
Vol 88 (2) ◽  
pp. 450-457 ◽  
Author(s):  
Marc Annaheim ◽  
Beatrice Lanzrein
Keyword(s):  
Symbiotic Association ◽  
Opposite Orientation ◽  
Double Stranded Dna ◽  
Circular Segment ◽  
Multiple Copies ◽  
Flanking Sequences ◽  
Terminal Repeats ◽  
First Time ◽  
Segmented Genome ◽  
Combined Data

Polydnaviruses are only found in symbiotic association with parasitic wasps within the families Ichneumonidae and Braconidae (ichnoviruses and bracoviruses). They have a segmented genome consisting of circular double-stranded DNA. In the proviral linear form they are integrated in the wasp's genome; in two bracoviruses, segments were found to be clustered. Proviral segments have direct terminal repeats. Segment excision has been proposed to occur through juxtaposition of these repeats by formation of a loop and recombination; one copy of the repeat then ends up in the circular segment and one in the rejoined DNA. Here we analysed the excision/circularization site of four segments of the Chelonus inanitus bracovirus (CiV) and found that they are similar to the two already known sites; on the basis of the combined data an extended excision site motif was found. Analyses of segment flanking sequences led to the first identification of one complete and several partial spacers between proviral segments in a polydnavirus. The spacer between the proviral segments CiV14 and CiV22.5 has a length of 2065 bp; the terminal repeats of CiV14 and CiV22.5 were seen to have an opposite orientation and from this a model on the spacial organization of the loops of the proviral cluster is proposed. Through various approaches it was shown that spacers are not excised or injected into the host. Measurement of relative abundances of various segments in proviral and excised form indicates for the first time that abundant segments are present in multiple copies in the proviral form.

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