Figure 5.
Comparison of mean TRF length, telomerase activity, and growth in TGFβ in early-passage 184B5 and subclones. (A) Subclones that did not maintain growth ± TGFβ or had only rare cells maintaining growth. Since most of the cells generated from these clones were used for assays, only 2–5 × 105 cells/clone were available for observation of ability to maintain growth in mass culture. Consequently, a rare cell capable of maintaining growth may not have been detected. Y17-βR represents the progeny of rare B5Y17 cells that maintained proliferation. (B) Subclones that maintained growth and showed a gradual increase in the ability of cells to maintain growth in the presence of TGFβ. (C) The heterogeneous B5Y16 clone and B5Y16 subclones. 16G-βR represents the progeny of a rare p24 colony that grew well in TGFβ and was clonally isolated. Assays were performed as described in MATERIALS AND METHODS and the Figure 1 legend.