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Simian virus 40 a gene function: Further characterization and growth of tsA transformed Chinese hamster cells
Author(s) -
Robinson Christine C.,
Lehman John M.
Publication year - 1982
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041110302
Subject(s) - chinese hamster , flow cytometry , microbiology and biotechnology , biology , immunofluorescence , hamster , cell culture , antigen , immunoprecipitation , dna synthesis , mitosis , virus , in vitro , virology , antibody , biochemistry , genetics
Abstract Chinese hamster embryo cells transformed with the tsA 58 mutant of Simian virus 40 express the transformed phenotype at the permissive temperature (33°C or 37°C) and a “normal” phenotype at the nonpermissive temperature (40.5°C). Immunofluorescence and immunoprecipitation of T antigens demonstrated that the “T” antigen (100 K) has an increase rate of synthesis and degradation at 40.5°C. However, the cells continue to replicate at the nonpermissive temperature when assayed by flow cytometry and autoradiography. This DNA synthesis was cellular, not viral, and not owing to an increase in DNA repair. When the cell cycle distributions of G 1 , S, and G 2 + M were assayed by the fraction labeled mitoses method, no differences were evident at the permissive and nonpermissive temperature; however, the doubling time was lengthened at 40.5°C, the tsA transformed cells are cycling and dying. However, if the transformed cells are seeded onto monolayers of normal Chinese hamster cells at 40.5°C, the cells are growth arrested when measured by growth assays, flow cytometry, autoradiography, and immunofluorescence for T antigen. Therefore, growth arrest can be obtained in tsA 58 transformed Chinese hamster cells when cocultured with normal Chinese hamster cells.