Time from stimulus to gene expression My understanding is that gene expression, in response to some stimulus, generally occurs on the order of minutes. I'm curious about the extremes...the quickest and the slowest cases. What is(are) the fastest time(s) recorded for genes being expressed in response to a stimulus? What are the slowest times?

The fastest I know of is the heat shock locus in _Drosophila_. The transcription factor (HSF) accumulates within about 30 seconds, and RNA Polymerase can be seen to start accumulating within 3 minutes.

Katie L. Zobeck, Martin S. Buckley, Warren R. Zipfel, John T. Lis. 2010. Recruitment Timing and Dynamics of Transcription Factors at the Hsp70 Loci in Living Cells. _Molecular Cell_ 40(6): 965-975