Resolution:
## Figure 5.
Representative cell cycle and cell density-related changes in Tag. Panel A shows the final cell density versus the initial plating density. Data representing
cells in exponential growth are expected to fit an approximate straight line. Data
that fall below an extrapolation of that line are at or are approaching density arrest.
Panel B shows that the fraction of cells in G_{1} increases as a function of density during exponential growth and plateaus as cells
arrest. Panels C and D show the G_{1} Tag expression as a function of the fraction of G_{1} cells (C) or cell density (D). The regions of data used to calculate the rate of
change in expression by linear regression are delineated (brackets) and the data used
to determine the terminal expression levels are marked (arrows).
Frisa and Jacobberger |