Parameter estimation.

Parameter values estimated by matching model outputs to observed data from FlyEx. Least squares fitting of model outputs to FlyEx with exhaustive search for the best combination of parameters on a regular grid suggests sensible values for the mRNA decay onset time, , in all three models. Regulated stability corresponds to an optimized period in time during which the mRNA is held stable and translated at a constant rate, followed by rapid decay. Unregulated stability is where the mRNA is allowed to decay from the very beginning; these parameters were estimated by forcing in the optimization loop.