Figure 2. Degradation kinetics of UTR-Seq reporters. (a-b).

Top: temporal (x-axis; hpf) mRNA levels (X; top y-axis, black dots, log₂-scale) and fitted decay kinetics (dashed light blue lines) of example reporters. Bottom: associated degradation function (b; bottom y-axis; dark-blue). Kinetic parameters are noted on plot. (a) Reporters that retained an early-onset decay had a constant degradation function with a single rate parameter (β, h^-1). (b) Reporters that fit a late-onset decay had a step-change degradation function with three parameters: initial rate (β₀, h^-1), final rate (β, h^-1) and onset-time (t₀, h). Both models also inferred the initial expression level of each reporter (X₀; top). (c) Fraction of A- (top, blue) and A+ (bottom, purple) reporters that fit early-onset (light colors, left) or late-onset (dark colors, right) degradation. Venn diagram shows overlap between A- (blue) and A+ (purple) late-onset classes. Numbers and percentages are noted on bars. (d) Distributions of degradation onset times (t₀, x-axis, hpf) of A- (blue) and A+ (purple) late-onset reporters (y-axis, % of reporters). (e) Distributions of degradation rates (β, h^-1, x-axis; labeled with half-life equivalents, h) of A- (blue) or A+ (purple) reporters (y-axis, % of reporters). Dashed lines represent distribution medians. See also Figure S4.