title: Cytoplasmic inheritance of rutamycin resistance in mouse fibroblasts.
abstract: Mouse fibroblasts resistant to the drug rutamycin were isolated by selectively introducing BrdUrd into the mitochondrial genome of a line of mouse fibroblasts (clone 1 D) lacking a cytoplasmic thymidine kinase enzyme. The ATPase (ATP phosphohydrolase; EC 3.6.1.3) activity of mitochondria isolated from these cells was resistant to rutamycin. The rutamycin-resistant mutants were enucleated with cytochalasin B and fused with mouse A 9 cells resistant to 8-azaguanine and sensitive to rutamycin. Cytoplasmic hybrids, or cybrids, were selected as cells resistant to rutamycin and 8-azaguanine, and appeared at a high frequency. Other fusions between rutamycin-resistant nucleated cells and A 9 produced colonies at a much lower frequency. Finally, fusions between enucleated clone 1 D cells and A 9 cells produced no rutamycin-resistant colonies. These results indicate that rutamycin resistance is a cytoplasmically inherited characteristic in this cell line.
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors; D000935:Antifungal Agents / Q000494:pharmacology*; D002459:Cell Fusion; D002701:Chloramphenicol / Q000494:pharmacology; D003593:Cytoplasm / Q000187:drug effects; D004351:Drug Resistance; D005111:Extrachromosomal Inheritance / Q000187:drug effects*; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology; D009154:Mutation; D012427:Rutamycin / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D012427:Rutamycin; D002701:Chloramphenicol; D000251:Adenosine Triphosphatases