A model with no technical noise

To begin, we performed a naive analysis, fitting joint unspliced and spliced count data using a conventional (5,7) stochastic transcriptional model, namely a two-stage birth-death process coupled to a bursting promoter:

where U and S are unspliced and spliced mRNA species; k, β, and γ are the rates of Markovian transcription, splicing, and degradation processes, respectively; and B is a geometrically distributed burst size with mean b. We assumed the system had reached its unique steady state. The generating function solution to this system has been reported by Singh and Bokes (7).