Peterson J A
Proc Natl Acad Sci U S A. 1976 Jun;73(6):2056-60. doi: 10.1073/pnas.73.6.2056.
The clonal variation in rate of albumin synthesis in hepatoma cells is described as a tool for the study of epigenetic control of differentiation. Previous studies have demonstrated that, from a population of hepatome cells, variant subclones can be readily isolated that produce albumin at different rates. Each clonal variant had a characteristic rate of albumin production, and the clones clustered around discrete values that formed a geometric progression. The present experiments, using a cell-free protein-synthesizing system from wheat germ; show that albumin messenger RNA activity is directly proportional to the rate of albumin synthesis in three different hepatoma clones, thus suggesting a pretranslational control of albumin production. Possible hypotheses to explain the geometric pattern of clonal variation are discussed with respect to the organization and control of the transcriptional unit.