Half-life values for 3′UTR-variant ζ-globin mRNAs. Transiently transfected HeLatTA cells were amended with tet, and levels of ζ-globin mRNA assessed at defined intervals relative to levels of endogenous tet-indifferent β-actin mRNA. The normalized level of ζ-globin mRNA at each time point is plotted relative to the normalized level at t = 0, which is arbitrarily assigned unit value. Each point depicts the mean ± SD value for at least three replicates. (A) Stable control ζWT mRNA. (B) ζ57 mRNA. (C) ζ49 mRNA. (D) ζ65 mRNA. (E) Unstable control ζARE mRNA. (F) Half-life and R2 values for curves in panels A-E, calculated from best-fit exponential decay curves with a fixed value of 1.0 at t = 0.