Phenotypic Expression in T-Lymphocyte x “Fibroblast” Cell Hybrids

1979 ◽  
pp. 224-231
Author(s):  
N. Saravia ◽  
R. I. DeMars ◽  
F. J. Bollum ◽  
F. H. Bach
Keyword(s):  
T Lymphocyte ◽  
Phenotypic Expression ◽  
Fibroblast Cell ◽  
Cell Hybrids

Activation and repression of a beta-globin gene in cell hybrids is accompanied by a shift in its temporal replication

1989 ◽  
Vol 9 (8) ◽  
pp. 3524-3532
Author(s):  
V Dhar ◽  
A I Skoultchi ◽  
C L Schildkraut
Keyword(s):  
Cell Line ◽  
Hybrid Cell ◽  
Globin Gene ◽  
Fibroblast Cell ◽  
Globin Genes ◽  
Fibroblast Cell Line ◽  
Beta Globin ◽  
Hybrid Cells ◽  
Beta Globin Gene ◽  
Cell Hybrids

To investigate whether a switch in the transcriptional activity of a gene is associated with a change in the timing of replication during the S phase, we examined the replication timing of the beta-globin genes in two different types of somatic cell hybrids. In mouse hepatoma (Hepa 1a) x mouse erythroleukemia (MEL) hybrid cells, the beta-globin gene from the MEL parent is transcriptionally inactivated and is later replicating than in the parental MEL cell line. In human fibroblast (GM3552) x MEL hybrid cells, the human beta-globin gene is transcriptionally activated, and all of the sequences within the human beta-globin domain (200 kilobases) we have examined appear to be earlier replicating than those in the parental fibroblast cell line. The chromatin configuration of the activated human beta-globin domain in the hybrids is relatively more sensitive to nucleases than that in the fibroblasts. Furthermore, major nuclease-hypersensitive sites that were absent in the chromatin flanking the distal 5' region of the human beta-globin gene cluster in the parental fibroblast cell line are present in the transcriptionally activated domain in the hybrid cell line. These results suggest that timing of replication of globin genes has been altered in these hybrid cells and thus is not fixed during the process of differentiation.

Quantification of expression of linked cloned genes in a simian virus 40-transformed xeroderma pigmentosum cell line

1985 ◽  
Vol 5 (7) ◽  
pp. 1685-1693
Author(s):  
M Protić-Sabljić ◽  
D Whyte ◽  
J Fagan ◽  
B H Howard ◽  
C M Gorman ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Cell Lines ◽  
Xeroderma Pigmentosum ◽  
Phenotypic Expression ◽  
Simian Virus 40 ◽  
Fibroblast Cell ◽  
Simian Virus ◽  
Selective Medium ◽  
Normal Human ◽  
Human Line

We wished to determine whether simian virus 40 (SV40)-transformed xeroderma pigmentosum cells, despite their defective DNA repair, were suitable for DNA-mediated gene transfer experiments with linked genes. Expression of a nonselectable gene (cat, coding for chloramphenicol acetyltransferase [CAT]) linked to a selectable gene (gpt, coding for xanthine-guanine phosphoribosyltransferase [XPRT]) in the plasmid pSV2catSVgpt was quantified after transfection of SV40-transformed xeroderma pigmentosum [XP20s(SV40)] and normal human [GM0637(SV40)] fibroblast cell lines. A novel autoradiographic assay with [3H]xanthine incorporation showed 0.5 to 0.7% phenotypic expression of XPRT in both cell lines. Without selection, transient CAT activity was 20 times greater in the GM0637(SV40) than in the XP20s(SV40) cells, and transient XPRT activity was 5 times greater. Both of these transient activities were increased and equalized in both cell lines by transfection with pRSVcat or pRSVgpt. Genotypic transformation to gpt+ occurred at a frequency of 2 X 10(-4) to 4 X 10(-4) in both cell lines with pSV2catSVgpt. After 2 to 3 months in selective medium, stable expression of the (nonselected) cat gene was found in 11 (92%) of 12 gpt-containing clones derived from GM0637(SV40) cells and in 13 (81%) of 16 gpt-containing clones from XP20s(SV40) cells. However, the levels of CAT activity did not correlate with those of XPRT activity, and both of these activities varied more than 100-fold among different clones. Copies (1 to 4) of the gpt gene were integrated in four clones of the GM0637(SV40) cells having an XPRT activity of 1 to 5 nmol/min per mg, but 5 to 80 copies were integrated in four XP20s(SV40) clones with an XPRT activity of 0.8 to 1.8 nmol/min per mg. This study shows that XP20s(SV40) is as suitable for gene transfer experiments as the normal human line GM0637(SV40).

scholarly journals Extinction of expression of the genes encoding haematopoietic cell-restricted transcription factors in T-lymphoma x fibroblast cell hybrids

Immunology ◽  
2001 ◽  
Vol 104 (2) ◽  
pp. 162-167 ◽  
Author(s):  
Tsuneyuki Oikawa ◽  
Toshiyuki Yamada ◽  
Nobuo Kondoh ◽  
Fumiko Negishi-Kihara ◽  
Yoshiaki Hitomi ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Fibroblast Cell ◽  
Cell Hybrids ◽  
Haematopoietic Cell ◽  
Genes Encoding ◽  
T Lymphoma

scholarly journals Quantification of expression of linked cloned genes in a simian virus 40-transformed xeroderma pigmentosum cell line.

1985 ◽  
Vol 5 (7) ◽  
pp. 1685-1693 ◽  
Author(s):  
M Protić-Sabljić ◽  
D Whyte ◽  
J Fagan ◽  
B H Howard ◽  
C M Gorman ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Cell Lines ◽  
Xeroderma Pigmentosum ◽  
Phenotypic Expression ◽  
Simian Virus 40 ◽  
Fibroblast Cell ◽  
Simian Virus ◽  
Selective Medium ◽  
Normal Human ◽  
Human Line

We wished to determine whether simian virus 40 (SV40)-transformed xeroderma pigmentosum cells, despite their defective DNA repair, were suitable for DNA-mediated gene transfer experiments with linked genes. Expression of a nonselectable gene (cat, coding for chloramphenicol acetyltransferase [CAT]) linked to a selectable gene (gpt, coding for xanthine-guanine phosphoribosyltransferase [XPRT]) in the plasmid pSV2catSVgpt was quantified after transfection of SV40-transformed xeroderma pigmentosum [XP20s(SV40)] and normal human [GM0637(SV40)] fibroblast cell lines. A novel autoradiographic assay with [3H]xanthine incorporation showed 0.5 to 0.7% phenotypic expression of XPRT in both cell lines. Without selection, transient CAT activity was 20 times greater in the GM0637(SV40) than in the XP20s(SV40) cells, and transient XPRT activity was 5 times greater. Both of these transient activities were increased and equalized in both cell lines by transfection with pRSVcat or pRSVgpt. Genotypic transformation to gpt+ occurred at a frequency of 2 X 10(-4) to 4 X 10(-4) in both cell lines with pSV2catSVgpt. After 2 to 3 months in selective medium, stable expression of the (nonselected) cat gene was found in 11 (92%) of 12 gpt-containing clones derived from GM0637(SV40) cells and in 13 (81%) of 16 gpt-containing clones from XP20s(SV40) cells. However, the levels of CAT activity did not correlate with those of XPRT activity, and both of these activities varied more than 100-fold among different clones. Copies (1 to 4) of the gpt gene were integrated in four clones of the GM0637(SV40) cells having an XPRT activity of 1 to 5 nmol/min per mg, but 5 to 80 copies were integrated in four XP20s(SV40) clones with an XPRT activity of 0.8 to 1.8 nmol/min per mg. This study shows that XP20s(SV40) is as suitable for gene transfer experiments as the normal human line GM0637(SV40).

Phenotype and surface antigens of mouse teratocarcinoma � fibroblast cell hybrids

1979 ◽  
Vol 5 (6) ◽  
pp. 739-752 ◽  
Author(s):  
Jean -Pierre Rousset ◽  
Philippe Dubois ◽  
Chantal Lasserre ◽  
Dominique Avil�s ◽  
Marc Fellous ◽  
...  
Keyword(s):  
Fibroblast Cell ◽  
Surface Antigens ◽  
Cell Hybrids ◽  
Mouse Teratocarcinoma

scholarly journals Activation and repression of a beta-globin gene in cell hybrids is accompanied by a shift in its temporal replication.

1989 ◽  
Vol 9 (8) ◽  
pp. 3524-3532 ◽  
Author(s):  
V Dhar ◽  
A I Skoultchi ◽  
C L Schildkraut
Keyword(s):  
Cell Line ◽  
Hybrid Cell ◽  
Globin Gene ◽  
Fibroblast Cell ◽  
Globin Genes ◽  
Fibroblast Cell Line ◽  
Beta Globin ◽  
Hybrid Cells ◽  
Beta Globin Gene ◽  
Cell Hybrids

To investigate whether a switch in the transcriptional activity of a gene is associated with a change in the timing of replication during the S phase, we examined the replication timing of the beta-globin genes in two different types of somatic cell hybrids. In mouse hepatoma (Hepa 1a) x mouse erythroleukemia (MEL) hybrid cells, the beta-globin gene from the MEL parent is transcriptionally inactivated and is later replicating than in the parental MEL cell line. In human fibroblast (GM3552) x MEL hybrid cells, the human beta-globin gene is transcriptionally activated, and all of the sequences within the human beta-globin domain (200 kilobases) we have examined appear to be earlier replicating than those in the parental fibroblast cell line. The chromatin configuration of the activated human beta-globin domain in the hybrids is relatively more sensitive to nucleases than that in the fibroblasts. Furthermore, major nuclease-hypersensitive sites that were absent in the chromatin flanking the distal 5' region of the human beta-globin gene cluster in the parental fibroblast cell line are present in the transcriptionally activated domain in the hybrid cell line. These results suggest that timing of replication of globin genes has been altered in these hybrid cells and thus is not fixed during the process of differentiation.

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