HYBRIDIZATION OF HAMSTER CELLS WITH HIGH AND LOW FOLATE REDUCTASE ACTIVITY

摘要: Abstract These studies concern the question whether diffusible repressors control syntheses of enzymes in mammalian cells. First, clonal sublines baby hamster kidney (BHK 21/13) cells culture were selected stepwise fashion for resistance to aminopterin. These survived concentrations aminopterin that up 104 times higher than those tolerated by wild-type because they contained 125 as much folate reductase, probably due overproduction enzyme. When five resistant hybridized lines, 32 35 hybrid clones intermediate levels reductase activity. This suggests is not loss a repressor.