A novel class of unstable 6-thioguanine-resistant cells from dog and human kidneys
✍ Scribed by Mitchell S. Turker; Raymond J. Monnat; Ken-Ichiro Fukuchi; Patricia A. Johnston; Charles E. Ogburn; Richard E. Weller; James F. Park; George M. Martin
- Publisher
- Springer
- Year
- 1988
- Tongue
- English
- Weight
- 842 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0742-2091
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✦ Synopsis
Thioguanine-resistant primary clones were grown from single cell suspensions obtained from dog and human kidneys by enzymatic digestion. In medium containing a relatively high concentration (lO#g/ml) of thioguanine, thioguanine-resistant primary clones arose from each source at frequencies ranging from 10 -4 to 10 -s. A reduction in total hypoxanthine uptake was found in the thioguanine-resistant primary clones which had developed in thioguanine medium, consistent with a reduction in hypoxanthine phosphoribosyltransferase activity. When these thioguanine-resistant primary clones were subsequently grown in the absence of thioguanine and assayed for the thioguanine-resistant phenotype and hypoxanthine phosphoribosyltransferase activity, it was found that most were now thioguanine-sensitive and yielded cell-free extracts with substantial amounts of hypoxanthine phosphoribosyltransferase activity. In contrast, thioguanine-resistant human clones grown continuously in the presence of thioguanine yielded cell-free extracts with little or no detectable hypoxanthine phosphoribosyltransferase activity. Southern blot analysis demonstrated no structural alterations in the hypoxanthine phosphoribosyltransferase gene in thioguanine-resistant primary human kidney clones. These results