The inherently stochastic nature of biomolecular processes is one of the main sources giving rise to cell‐to‐cell variations in protein and mRNA abundance, termed noise. Noise in isogenic populations can enhance survival under adverse conditions and stress, and has therefore played a fundamental role in evolution. On the other hand, noise may have detrimental effects and therefore cells must also display robustness to fluctuations and possess mechanisms of control in order to function properly. Noise can be introduced at every step in the cascade of intermediate events resulting in the production of functional proteins. While initial studies of noise focused on stochasticity introduced at the transcriptional level, recent years have witnessed a gradual shift of emphasis into the effects that post‐transcriptional processes have on phenotypic noise. Here, we survey the insights that have been gained on the effects of processes that modify RNA transcript populations on phenotypic noise, including regulation by noncoding RNAs in prokaryotes and eukaryotes, alternative splicing and transcriptional interference. WIREs RNA 2014, 5:197–207. doi: 10.1002/wrna.1209

This article is categorized under:

• RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes
• RNA Processing > RNA Editing and Modification
• Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs
• RNA in Disease and Development > RNA in Development