Parsimonious two-state model. This two-state model is able to fit all of the decay patterns in Figure 2, by an appropriate choice of the three fitting parameters, λ, µ, ν. In this context, the mRNA is initially in the state A. From this state it can be degraded directly with a rate µ or change biochemical state, with rate λ, from which it is then degraded with rate ν. Although this network performs a better fit of the data and is preferred to the exponential fitting based on the AIC criterion, the interpretation of the states is unclear. The fitting curves and the parameters are discussed in Additional file 1.