Observed on a microscope slide, a living cell appears serene. But underneath its tranquil facade, it buzzes with biochemical chatter. The DNA genome inside every cell of a plant or animal contains many thousands of genes. Left to its own devices,
the transcription machinery of the cell would express every gene in the genome at once: unwinding the DNA double helix, transcribing each gene into single-stranded messenger RNA and, finally, translating the RNA messages into their protein forms.
This article was originally published with the title Censors of the Genome.