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DNA synthesis and mitosis in a temperature sensitive Chinese hamster cell line
Author(s) -
Roscoe D. H.,
Robinson Hildred,
Carbonell A. W.
Publication year - 1973
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.1040820303
Subject(s) - mitosis , chinese hamster , dna synthesis , incubation , biology , microbiology and biotechnology , dna , cell cycle , cell culture , cell division , mutant , cell , biochemistry , genetics , gene
Viability, DNA synthesis and mitosis have been followed in the temperature sensitive Chinese hamster cell mutant K12 under permissive and non‐permissive conditions. On incubation at 40°C cells retained their ability to form colonies at 33°C for 15 to 20 hours, but viability was lost gradually during the following 20 hours. When random cultures of K12 were shifted to 40°C the rate of DNA synthesis was normal for three to four hours but then decreased markedly, reaching 95% inhibition after 24 hours. Under the same conditions mitosis was inhibited after 15 hours. If cultures which had been incubated at 40°C for 16 hours were placed at 33°C the rate of DNA synthesis increased five hours after the shift down and mitosis 18 hours after. These results can be interpreted on the assumption that K12 at 40°C is unable to complete a step in the cell cycle which is essential for DNA synthesis and which occurs three to four hours before the start of S at 33°C.