The segmentation clock, which forms repeated body structures during development, generates many oscillating RNAs that regulate common developmental pathways.

When bacteria are starved, a small RNA inhibits transcription by folding to mimic a legitimate promoter target, after which adding nucleotides can restart transcription.

Activation of a two-component signaling pathway required for Salmonella virulence triggers a burst of transcription that may allow rapid adaptation to new conditions.