The future is noisy: on the role of spatial fluctuations in genetic switching

A genetic switch may be realised by a certain operator sector on the DNA strand from which either genetic code, to the left or to the right of this operator sector, can be transcribed and the corresponding information processed. This switch is controlled by messenger molecules, i.e., they determine to which side the switch is flipped. Recently, it has been realised that noise plays an elementary role in genetic switching, and the effect of number fluctuations of the messenger molecules have been explored. Here we argue that the assumption of well-stirredness taken in the previous models may not be sufficient to characterise the influence of noise: {\em spatial} fluctuations play a non-negligible part in cellular genetic switching processes.