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Revertants of adenovirus type‐12‐transformed hamster cells have lost part of the viral genomes
Author(s) -
Groneberg J.,
Doerfler W.
Publication year - 1979
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910240112
Subject(s) - biology , dna , hamster , microbiology and biotechnology , cell culture , genome , transformation (genetics) , mastadenovirus , adenoviridae , virology , gene , genetics , recombinant dna
The cell line T637 was derived from BHK21 cells (subline B3) by transformation with adenovirus type 12. The T637 cells contain multiple copies of the viral DNA, with different parts of the viral genomes being represented in unequal amounts. The persisting viral DNA has been shown in previous work to be covalently linked to cellular DNA. In the present report, the isolation and characterization of 18 morphological revertants of the T637 line are described. The T637 cells are round and epithelioid, the revertants are fibroblasts. The revertants arose spontaneously and could be enriched by letting the T637 culture grow to very high density; the T637 cells detached from the plastic surface, whereas the revertants stayed attached and could then be cloned. The morphological revertants of T637 cells differed from both the B3 and the T637 lines in a number of biological properties, such as saturation density, growth rate, agglutinability by plant lectins and uptake of low‐molecular‐weight compounds. The revertants were all T‐antigen negative, but reacted with anti‐LETS serum (antiserum against the large external transformation‐sensitive protein). The B3 and T637 cells were LETS‐negative. The revertants exhibited a pseudodiploid karyotype. All of the 18 revertants could be transplanted into 4‐week‐old Syrian hamsters, although most of the revertants grew less rapidly than the B3 cells. The patterns of integration of adenovirus type‐12 DNA were investigated using the DNA‐DNA hybridization technique of Southern. Some of the revertant lines (TR3, TR7, TR16, and F10) appeared to have lost almost all viral DNA sequences; the other revertant lines lacked several of the viral DNA sequences present in the T637 line. Upon superinfection of the T637 line and all of the revertants with adenovirus type 2 (Ad2), Ad2 replication was inhibited in T637 cells. In the revertants, however, Ad2 grew as efficiently or even more so than in the B3 line.