Bring in the Noise


Noise obscures meaningful information. Noise is what ruins your carefully designed synthetic biology gene circuit. But noise is part of life and life, it turns out, needs noise. There’s a terrific review article in this week’s Nature discussing recent theoretical and experimental work on biological noise showing functional roles for molecular, genetic, and evolutionary noise.

From the abstract:

The genetic circuits that regulate cellular functions are subject to stochastic fluctuations, or ‘noise’, in the levels of their components. Noise, far from just a nuisance, has begun to be appreciated for its essential role in key cellular activities. Noise functions in both microbial and eukaryotic cells, in multicellular development, and in evolution. It enables coordination of gene expression across large regulons, as well as probabilistic differentiation strategies that function across cell populations. At the longest timescales, noise may facilitate evolutionary transitions.

Of course I am most interested in what this research means for synthetic biology, where the focus often lies on the elimination or reduction of noise through buffered genetic feedback circuits. But what if noise has to be part of a circuit in order for proper function?

As an impediment to the design of deterministic circuits, noise is a nuisance. But a new wave of studies is showing how noise can, and does, provide critical functions that would be difficult or impossible to achieve by (hypothetical) deterministic gene circuits.

Maybe gene expression stochasticity ain’t noise pollution after all!

Thanks for the link Michael!