[ Follow Ups ]
Posted by Peter Zandstra on December 17, 1999 at 16:12:58:
In Reply to: Re: B cell committment posted by Jim on November 04, 1999 at 08:26:40:
Great to join the discussion on this interesting paper - I'll give the forum my engineering view on it.....
I think the key results lie in the results of the Bcl-2 Pax-/- cells in the absence vs the presence of exogenous factors.
In the absence of any "stabilizing" signal, a stochasticly determined pattern of differentiated cell types is seen - the identity of the resultant cells "stochastically" determined by the transcription factor profile.
Interestingly, in the presence of exogenous factors (ones specific to particular lineages) the preferential production of those cells is seen. This too makes sense if one allows for the exogenous factos to promote "threshold stabilzation" of particular subsets of expressed transcription factors.
What I do not agree with, and is an almost "throw away" statement,is the last sentence "supporting stochastic differentiation". To the contrary, it seems stochastic differentation only occours in the null situation and that under "normal curcumstances" this process is actually exogenously regulated. Now "Nutt et al." actually seem to be referring to the orgiginal Pax expression of the cells as stochastic. Althought they show no data for this, as they suggest that this too may be thrshold based, the arguments above lead me to question this conclusion.
Is this interpertation out of line?
-- Peter