Hi,

This question might be really stupid, but I'm a beginner and information on this would help a lot: I would like to know what exactly people mean when they refer to "steady state mRNA". Could someone help please?

Thanks,  
Rama
from this <a href="http://www.nature.com/msb/journal/v8/n1/full/msb201223.html">paper</a>:

> We assume that the change of mRNA level (dR/dt) depends linearly on mRNA synthesis and degradation,
  
> dR/dt = txj[DNA] - dj[RNAj]
  
> where [RNAj] is the RNA concentration for gene j, [DNA] is constant ([DNA]=1), txj is the transcription rate, and dj is the degradation rate of gene j. For simplification, we initially assume the degradation rate to be constant, meaning independent of gene j. Therefore in steady state where dR/dt=0, the RNA concentration of gene j is proportional to transcription and degradation rates of gene j.