Figure S1 - Transient Phenomena in Gene Expression after Induction of Transcription

Lifetime densities and evolution of the average number of mRNAs. In panel (a) we show the lifetime density as given in Eq. (2) with different shape parameters and fixed average lifetime density min (red: , solid blue: , dashed blue: , solid green: , dashed green: ). For fixed the variance of the distribution scales as . Each lifetime distribution leads to a different pattern of the growth of the mRNA number, , according to Eq. (6) (Panel (b)). The time to a steady state amount depends critically on the shape parameter - the larger the faster a steady state is attained. Conversely, for small parameters such as a steady state is reached only after about min despite an average lifetime of min. Note that the gamma density describes a large variety of possible mRNA lifetime distributions, although for non-integer values of the shape parameter there is no clear relationship to the number of biochemical steps related to degradation. (EPS)