In support of this idea, it has been shown that bacteria can switch stochastically into a "persistent" state which has slow growth coupled with an ability to survive antibiotic treatment.
[8] Moreover, noisy genes are associated with a distinct promoter architecture, including the prevalence of TATA boxes, consistent with the theoretical predictions that noise is greatly influenced by the logic of the transcriptional process itself and, in particular, the transition from closed to open chromatin.
For example, the patterning of the adult fly eye relies on multiple alternative choices of differentiation pathways within an apparently homogeneous field of cells.
This ability to buffer variations generated by molecular noise, genetic polymorphism, or environmental fluctuations is termed robustness.
For example, in the development of the repeating blocks of somites in the mesoderm of vertebrate animals, even though the biological system may be subject to a noisy environment, the segmentation clock maintains periodic gene expression through coupled oscillators, in which synchronous oscillation of neighbors is maintained through mutual coupling.
This mechanism enables embryos to maintain a constant segregation of somites, despite the noise imposed by the high level mitosis required for continued growth.
Recent studies suggest that this noise has multiple sources, including the stochastic or inherently random nature of the biochemical reactions of gene expression.